EXHIBIT 10.6

              [LETTERHEAD OF WENBERG REALTY COMPANY APPEARS HERE]


This Lease, made at SAN FRANCISCO, CALIFORNIA this 4TH day of  APRIL, 1995, by
               and between PLEASANT HILL INDUSTRIAL PARK ASSOCIATES A CALIFORNIA
               LIMITED PARTNERSHIP

PARTIES        and  TUTSYSTEMS, INC.

               hereinafter called respectively Lessor and Lessee, without regard
               to number or gender,

PURPOSE             WITNESSETH: That Lessor hereby leases to Lessee, and Lessee
               hires from Lessor, for the purpose of conducting therein the
               development, sales and distribution of electronic products and
               related uses and for no other purpose, those certain premises
               with the appurtenances, situated in the City of Pleasant Hill

PREMISES       County of Contra Costa, State of California, and more
               particularly described as follows, to-wit

               Approximately 11,170 square feet more commonly known and
               designated as 2495 Estand Way, Pleasant Hill, California.

TERM                The term shall be for THREE (3)---------------------------
               years commencing on the 1st day of JUNE , 1995, and ending on the
               31st day of MAY , 19 98, at the following rent in lawful money of
               the United States of America, which Lessee agrees to pay to
               Lessor, without deduction or offset, at such place or places as
               may be designated from time to time by Lessor, in installments as
               follows:

RENT

               The sum of NINE THOUSAND ONE HUNDRED TWENTY-SEVEN AND 50/100
               ($9,127.50) DOLLARS on the first day of June, 1995 and the
               further sum of NINE THOUSAND ONE HUNDRED TWENTY-SEVEN AND 50/L00
               ($9,127.50) DOLLARS on the first day of each and every month
               thereafter to and including the first day of November, 1996;
               thereafter the sum of NINE THOUSAND NINE HUNDRED SEVENTY-NINE AND
               40/100 ($9,979.40) DOLLARS on the first day of December, 1996 and
               the further sum of NINE THOUSAND NINE HUNDRED SEVENTY-NINE AND
               40/100 ($9,979.40) DOLLARS on the first day of each and every,
               month thereafter to and including the first day of May, 1998.

LEASE          All rent payments should be made payable to LOWENBERG
               -----------------------------------------------------
               CORPORATION.
               ------------

                 It is further mutually agreed between the parties as follows:

POSSESSION          1. If Lessor, for any reason whatsoever, cannot deliver
               possession of the said premises to Lessee at the commence of
               the said term. as hereinbefore specified, this lease shall not be
               void or voidable, nor shall Lessor be liable Lessee for any loss
               or damage resulting therefrom; but in that event there shall be a
               proportionate deduction of recovering the period between the
               commencement of the said term and the time when Lessor can
               deliver possession.

WASTE               2. Lessee shall not commit, or suffer to be committed, any
ALTERATIONS    waste upon the said premises, or any nuisance, or other act or
               thing which may disturb the quiet enjoyment of any other tenant
               in the building in which the demised premises may be located.
               Lessee shall not make, or suffer to be made, any alterations of
               the said premises, or any part thereon without the written
               consent of Lessor first had and obtained, and any additions to,
               or alterations of, the stud premises except movable furniture and
               trade fixtures, shall become at once a part of the realty and
               belong to Lessor.

 
ABANDONMENT         3. Lessee shall not vacate or abandon the premises at any
               time during the term; and if Lessee shall abandon, vacate or
               surrender said premises, or be dispossessed by process of law, or
               otherwise, any personal property belonging to Lessor and left on
               the premises shall be deemed to be abandoned, at the option of
               Lessor, except such property as may be under a security agreement
               with Lessor.

USES                4. Lessee shall not use, or permit said premises, or any
PROHIBITED     part thereof, to be used, for any purpose or purposes other than
               the purpose or purposes for which the said premises are hereby
               leased; and no use shall be made or permitted to made of the said
               premises, nor acts done, which will increase the existing rate of
               insurance upon the building in which said premises may be
               located, or cause a cancellation of any insurance policy covering
               said building, or any part there nor shall Lessee sell, or permit
               to be kept, used, or sold, in or about said premises, any article
               which may be prohibited the standard form of fire insurance
               policies. Lessee shall, at his sole cost and expense, comply with
               any and all requirements, pertaining to said premises, of any
               insurance organization or company, necessary for the maintenance
               reasonable fire and public liability insurance, covering said
               building and appurtenances.

FREE                5. Lessee shall keep the demised premises and the property
FROM LIENS     in which the demised premises are situated, free from: any liens
               arising out of any work performed, materials furnished, or
               obligations incurred by Lessee.

COMPLIANCE          6. Lessee shall, at his sole cost and expense, comply with
WITH           all of the requirements of all Municipal, State and Federal
GOVERNMENTAL   authorities now in force, or which may hereafter be in force,
REGULATIONS    pertaining to the said premises, and shall faithfully observe 
               in the use of the premises all Municipal ordinances and State and
               Federal statutes now in force or which may hereafter in force.
               The judgment of any court of competent jurisdiction, or the
               admission of Lessee in any action or proceed against Lessee.
               whether Lessor be a party thereto or not, that Lessee has
               violated any such ordinance or statute in the of the premises,
               shall be conclusive of that fact as between Lessor and Lessee.

INDEMNIFICA-        7. Lessee, as a material part of the consideration to be
TION OF        rendered to Lessor, hereby waives all claims against Lessor for
LESSOR         damages to goods, wares, merchandise and other personal property,
               in, upon or about said premises and for injures to persons in or
               about said premises, from any cause arising at any time, and
               Lessee will hold Lessor exempt and harm from any damage or injury
               to any person, or to the goods, wares, merchandise and other
               personal property of any per arising from the use of the premises
               by Lessee, or from the failure of Lessee to keep the premises in
               good condition repair, as herein provided.

UTILITIES           8. Lessee shall pay for all water, gas, heat, light, power,
               telephone service, sewer service charge and all other services:
               supplied to the said premises, together with any taxes thereon.

ENTRY BY            9. Lessee shall permit Lessor and his agents to enter into
LESSOR         and upon said premises at all reasonable times for the pose of
               inspecting the same or for the purpose of maintaining the
               building in which said premises are situated, or for purpose of
               making repairs, alterations or additions to any other portion of
               said building, including the erection maintenance of such
               scaffolding, canopies, fences and props as may be required, or
               for the purpose of posting notice non-liability for alterations,
               additions, or repairs, or for the purpose of placing upon the
               property in which the premises are located any usual or ordinary
               for sale signs, without any rebate of rent and without any
               liability to Lessee for any loss of occupation or quiet enjoyment
               of the premises thereby occasioned; and shall permit Lessor, at
               any within thirty days prior to the expiration of this lease, to
               place upon said premises any usual or ordinary "to signs.

DESTRUCTION         10. In the event of a partial destruction of the said
OF             premises during the said term. from any cause. Lessor forthwith
PREMISES       repair the same. provided such repairs can be made within sixty
               (60)days under the laws and regulations State, Federal, County or
               Municipal authorities, but such partial destruction shall in no
               wise annul or void this lease except that Lessee shall be
               entitled to a proportionate deduction of rent while such repairs
               are being made, such proportionate deduction to be based upon the
               extent to which the making of such repairs shall interfere with
               the business carried on by Lessee in the said premises. If such
               repairs cannot be made in sixty (60) days, Lessor may, at his
               option, same within a reasonable time, this lease continuing in
               full force and effect and the rent to be proportionately rebate
               aforesaid in this paragraph provided. In the event that Lessor
               does not so elect to make such repairs which cannot made in sixty
               (60) days, or such repairs cannot be made under such laws and
               regulations, this lease may be terminate the option of either
               party. In the event that the building in which the demised
               premises may. be situated be destroy the extent of not less than
               33 1/3% of the replacement cost thereof, Lessor may elect to
               terminate this lease, whether demised premises be injured or not.
               A total destruction of the building in which the said premises
               may be situated terminate this lease. Lessee waives any right to
               terminate this lease as a result of any statutory provision now
               or here in effect pertaining to the damage or destruction of the
               demised premises or the building of which the demised premises
               are a portion except as expressly provided herein.

ASSIGNMENT          11. Lessee may assign this lease or any interest therein and
AND            may also sublet the whole of said premises, provide written
SUBLETTING     consent of Lessor to any such assignment or subletting is first
               obtained by Lessee. If, during the term of this Lessee requests
               the written consent of Lessor to any such assignment or
               subletting, Lessor's consent thereto shall unreasonably be
               withheld. A consent to one assignment or subletting shall not be
               deemed to be a consent to any subsequent assignment or
               subletting, and any such subsequent assignment or subletting
               without Lessor's consent shall be and shall, at Lessor's option,
               terminate this lease. This lease shall not, nor any interest
               therein, be assignable the interest of Lessee by operation of law
               without the written consent of Lessor, but such shall not
               unreasonably be withheld. In the event that the demised premises
               are assigned or subleased at a rental consideration in excess of
               the then current rent, then all of such excess shall be paid to
               the lessor as additional rent thereunder.

 
INSOLVENCY          12. In addition to any and all rights or remedies of Lessor
OR             hereunder or as provided by law, the term of this Lease may be
BANKRUPTCY     ended at the option of Lessor and Lessor, at its option, may
               reenter and take possession of the demised premise and remove all
               persons therefrom and, upon the exercise of such option by
               Lessor, Lessee shall have no further claim in or to the demised
               premises, and the Lease Agreement and any interest in or to the
               demised premises shall no longer be an asset of the Lessee or any
               successor in interest, if any one or more of the following events
               occur:

                    (a) Lessee admits in writing its inability to pay its debts
               as they come due;

                    (b) Lessee makes, to its unsecured creditors generally, an
               offer of settlement, extension or composition;

                    (c) Lessee makes an assignment for the benefit of creditors;

                    (d) Lessee files any petition or action for relief under the
               provisions of any bankruptcy, reorganization, insolvency or
               moratorium law, or any other law or laws for the relief of, or
               relating to, debtors;

                    (e) Lessee is the subject of an involuntary petition or
               similar action for relief under any bankruptcy, reorganization
               insolvency, or moratorium law, or any other law or laws for the
               relief of, or relating to, debtors;

                    (f) A receiver or trustee is appointed, with or without
               Lessee's consent, to take possession of all or part of the assets
               or properties of Lessee.

                    In the event that any one or more of the preceding events
               shall occur, failure by Lessor to assert immediately its right to
               reenter and take possession of the demised premises or to
               exercise any other rights or remedies granted to Lessor by law,
               or hereunder shall not constitute a waiver of any such right or
               remedy nor shall Lessor be estopped to assert, at a late time,
               any such right or remedy.

DEFAULT             13. In the event of any breach of this lease by Lessee, then
               Lessor, besides other rights and remedies he may have shall have
               the immediate right of re-entry and may remove all persons and
               property from the premises. If Lessor`s right (re-entry is
               exercised following abandonment of the premises by Lessee, then
               Lessor may consider any personal property belonging to Lessee and
               left on the premises to also have been abandoned, in which case
               Lessor may dispose of all such personal property in any manner
               Lessor shall deem proper and is hereby relieved of all liability
               for doing so.

                    If Lessee breaches this lease and abandons the property
               before the end of the term, or if Lessee's right to possession
               terminated by Lessor because of a breach of the lease, then in
               either such case, Lessor may recover from Lessee a damages
               suffered by Lessor, as the result of Lessee's failure to perform
               his obligations hereunder, including, but not, restricted to, the
               worth at the time of the award by the court having jurisdiction
               thereof of the amount by which the re then unpaid hereunder for
               the balance of the lease term exceeds the amount of such rental
               loss for the same period which Lessee proves could be reasonably
               avoided by Lessor, and in such case, Lessor, prior to the award,
               may relet the premises for the purpose of mitigating damages
               suffered by Lessor because of Lessee s failure to perform his
               obligation hereunder; provided, however, that even though Lessee
               has abandoned the premises raises following such breach, this
               lease shall nevertheless continue in full force and effect for as
               long as Lessor does not terminate Lessee's right of possession,
               or until such termination, Lessor may enforce all his rights and
               remedies under this lease, including the right to recover the
               rent from Lessee as it becomes due hereunder.

REPAIRS             14. Lessee shall, at his sole cost, keep and maintain said
               premises and appurtenances and every part thereof (excepting
               exterior walls and roofs which Lessor agrees to repair),
               including glazing, silks adjacent to said premise parking areas,
               driveways, lighting standards, landscaping and Striping. any
               store front and the interior of the premises in good and sanitary
               order, condition and repair, hereby waiving the benefits of any
               statute now or hereafter in effect which would otherwise afford
               Lessee. the right to make repairs at Lessor's expense or to
               terminate this lease because Lessor s failure to keep the
               premises in good order, condition and repair. By entry hereunder,
               Lessee accepts the premises as being in good and sanitary order,
               condition and repair and agrees on the last day of said term. or
               sooner termination of this lease, to surrender unto Lessor all
               and singular said premises with said appurtenances in the same
               condition when received, reasonable use and wear thereof and
               damage by fire. act of God or by the elements excepted, and
               remove all of Lessee's signs from said premises.

ADVERTISE-          15. Lessee shall not conduct or permit to be conducted any
MENTS AND      sale by auction on said premises. Lessee shall not place permit
SIGNS          to be placed any projecting sign, marquee or awning on the front
               of the said premises without the written consent of Lessor;
               Lessee, upon request of Lessor, shall immediately remove any sign
               or decoration which Lessee has placed permitted to be placed in,
               on, or about the front of the premises and which, in the opinion
               of Lessor, is objectionable offensive, and if Lessee fails so to
               do, Lessor may enter upon said premises and remove the same.
               Lessor has reserved to exclusive right to the two exterior
               sidewalls, rear wall and roof of said premises, and Lessee shall
               not place or permit to be placed upon the said sidewalls, rear
               wall or roof, any sign, advertisement or notice without the
               written consent of Lessor.

SURRENDER           16. The voluntary or other surrender of this lease by
OF LEASE       Lessee, or a mutual cancellation thereof, shall not work merger,
               and shall, at the option of the Lessor, terminate all or any
               existing subleases or subtenancies, or may, at the option of
               Lessor. operate as an assignment to him of any or all such
               subleases or subtenancies.

CONDEMNATION        17. If any part of the demised premises shall be taken or
               condemned for a public or quasi-public use, and a part thereof
               remains which is susceptible of occupation hereunder, this lease
               shall, as to the part so taken, terminate as of the date title
               shall vest in the condemnor, and the rent payable hereunder shall
               be adjusted so that the Lessee shall be required to pay for the
               remainder of the term only such portion of such rent as the value
               of the part remaining after condemnation bears to the value of
               the entire premises at the date of condemnation; but in such
               event Lessor shall have the option to terminate this lease as of
               the date when title to the part so condemned vests in the
               condemnor. If all of

 
               demised premises, or such part thereof be taken or condemned so
               that there does not remain a portion susceptible for occupation
               hereunder, this lease shall thereupon terminate. If a part or all
               of the demised premises be taken or co condemned, all
               compensation awarded upon such condemnation or taking shall go to
               the Lessor and the Lessee shall ha no claim thereto, and the
               Lessee hereby irrevocably assigns and transfers to the Lessor any
               right to compensation damages to which the Lessee may become
               entitled during the term hereof by reason of the condemnation of
               all or a part of the demised premises.


ATTORNEY'S          18. In case suit is brought by either party because of the
FEES           breach of any term, covenant or condition herein contained the
               prevailing party shall be entitled to recover against the other
               party a reasonable attorney's fee to be fixed by the court

ARBITRATION         19. In the event of a dispute between Lessor and Lessee
               relative to the provisions of this lease, the matter shall
               determined by competent and disinterested arbitrators, one of
               whom shall be selected and paid by Lessor and c selected and paid
               by Lessee. Each party shall notify the other party the name and
               address of the arbitrator so select within 15 days after a
               written request for arbitration has been given by one party to
               the other. In the event these two c not agree within 30 days
               after their appointment, the arbitrators shall select a competent
               and disinterested party as ~ third arbitrator, the expense to be
               borne equally by Lessor and Lessee. In the event these two do not
               so select a third arbitrator within the next 15 days. then the
               third arbitrator shall be appointed by the President of the
               Chamber of Commerce of San Francisco, State of California, upon
               the request of either party. The decision of any two of the three
               arbitrators so chosen shall be final and conclusive on the
               parties hereto. The decision of the arbitrators shall be in
               writing and a copy thereof shall be given to Lessor and Lessee
               within 90 days after the date of the request for arbitration.

SECURITY            20.  Lessee shall deposit with Lessor upon execution hereof
DEPOSIT        the sum of $10,223.25 to be transferred from existing deposits on
                          ------------------------------------------------------
               2446 and 2450 Estand Way, Pleasant Hill, CA (Lease dated 7/26
               -------------------------------------------------------------
               Extensions dated ($10,223.25) Dollars as security for Lessee's
               -----------------------------
               faithful performance of Lessee's obligations hereunder, Lessee
               fails to pay rent or other charges due hereunder, or otherwise
               defaults with respect to any provision of this lea Lessor may
               use, apply or retain all or any portion of said deposit for the
               payment of any rent or other charge in default, for the payment
               of any other sum to which Lessor may become obligated by reason
               of Lessee's default, or to compensation Lessor for any loss or
               damage which Lessor may suffer thereby. If Lessor so uses or
               applies all or any portion of such deposit. Lessee shall within
               ten (10) days after written demand therefor, deposit cash with
               Lessor in an amount sufficient to restore said deposit to the
               full amount hereinabove stated and Lessee's failure to do so
               shall be a breach of this Lessee and Lessor may at its option
               terminate this lease. Lessor shall not be required to keep said
               deposit separate from general accounts. If Lessee performs all of
               Lessee's obligations hereunder, said deposit or so much thereof
               as had theretofore been applied by Lessor, shall be returned
               without payment of interest or other increment for its use, to
               Lessor (or, at Lessors option, to the last assignee, if any, of
               Lessee's interest hereunder) within fifteen (15) days after the
               expiration of the term thereof, or after Lessee has vacated the
               premises, whichever is later.

TAXES AND           21. In the event that in any tax year during the term of
ASSESSMENTS    this lease the amount of the Municipal, State or County Federal
               Estate taxes including the amount of any general or special
               assessments, or levies or charges made by any municipal political
               subdivision for local improvements shall exceed the amount of
               such taxes including such general or special assessments, levies
               or charges for the fiscal year 1994 - 1995, the Lessee shall pay
               to the Lessor for such year upon demand an amount equal to 12 %
               of the total increase in such taxes, assessments, levies and
               charges upon whole of the land and building upon and within which
               the leased premises are situate, whether such increase is caused
               increased or added rate or increased assessed valuation or by
               increase in, or by reason of any new, general or special
               assessment. It is understood that, if the right to pay any
               assessments in installments is given to Lessor then for the poses
               of this paragraph it shall be deemed that the same are paid in
               such installments regardless of whether or not Lessor may pay the
               same in one sum or in any larger amounts than the installment
               basis.

                    It is agreed that any increase in taxes caused by an
               increase in assessed valuation due to work done in the demised
               premises by Lessee or by work done in any other parts of the
               building by Lessor or any other tenant in the building s not be
               included in computing the amount of increase in taxes to be paid
               by Lessee under the preceding paragraph of Paragraph 21, but
               shall be computed separately in the following manner:

                    1. Any increase in taxes caused by an increase in assessed
               valuation due to the work done by Lessee in the demised premises
               at any time during said term shall be borne entirely by Lessee.

                    2. If there is any increase in taxes caused by work done in
               any other parts of the building by Lessor or by any of tenant in
               the building, the Lessee shall not be responsible for any portion
               of such increase in taxes.

                    The amount of Lessee's obligation under this paragraph for
               the year in which this lease terminates shall be prorated. in the
               proportion that the period this lease is in effect during the tax
               year in which this lease terminates bears to the tax year.


                    Lessee also shall pay, before delinquency, any and all taxes
               levied or assessed and which become payable during term hereof
               upon Lessee's equipment, furniture, fixtures and other personal
               property located in the premises: In a tion to rental and other
               charges to be paid by Lessee hereunder, Lessee shall reimburse to
               Lessor, upon demand, any all taxes payable by Lessor (other than
               net income taxes) whether or not now customary or within the
               contemplation the parties hereto; (a) upon, allocable to, or
               measured by or on the rental patentable hereunder, including,
               without limitation, any gross income tax or excise tax levied by
               the State, any political subdivision thereof, or Federal
               Government respect to the receipt of such rental: or (b) upon or
               with respect to the possession, leasing, operation, management

 
               maintenance, alteration, repair, use or occupancy by Lessee of
               the premises or any portion thereof; or (c) upon or measured by
               the value of Lessee's equipment, furniture, fixtures and other
               personal property located in the premises or by the cost or
               value of any leasehold improvements located in the premises; or
               (d) upon this transaction or any document to which Lessee is a
               party creating or transferring an interest or an estate in the
               premises; or (e) any tax or charge made by any authority having
               jurisdiction upon any automobile parking facilities used by
               Lessee and any sewer tax, water control tax or Environmental
               Quality Control charge.


ADJUSTMENT          22. The monthly rental in the amount of $9,979.40, set forth
IN RENT        above shall be increased on JUNE 1, 1998

               in the same proportion that the Consumer Price Index figure
               published by the United States Department of Labor Bureau of
               Labor Statistics, all items retail for San Francisco-Oakland for
               the month prior to the adjustment month bears to the Consumer
               Price Index figure for the month prior to the month in which
               lease commences (1967 = 100) hereinafter called "basic index
               figure, provided, however, that in no event shall the monthly
               rental for any such period be less than the monthly rental being
               paid by Lessee immediately prior to such adjustment.

                    If prior to the effective date of any rental adjustment the
               Bureau of Labor Statistics should revise or change the methods or
               basic data used in calculating the said index, in such a way as
               to affect the direct comparabiluty of such revised or changed
               index, with the original index used herein, then the Bureau shall
               be requested to furnish a conversion factor designed to adjust to
               the new basis, the said original index.

                    If said Consumer Price Index, as now constituted, compiled
               and published shall cease to be compiled and publish during the
               term hereof, then the Bureau of Labor Statistics shall be
               requested to furnish a statement conveying the basis index figure
               to a figure that would be comparable in another index published
               by the Bureau of Labor Statistics and such other index shall be
               used in computing the rental increase provided above.

                    If no such conversion or other index is available, then the
               said rental increase shall be determined by arbitration the
               manner provided in Paragraph 19 hereof.

INSURANCE           23. Lessee agrees during the full term of this lease to
               carry comprehensive bodily injury insurance covering the demised
               premises, its appurtenances and ways immediately adjoining,
               including any parking areas and driveways that may be used by
               Lessee, in a single limit of $1,000,000 for injury or death to
               any number of persons in any one occurrence, property damage
               insurance in the amount of $100,000.00 and plate glass insurance
               in Companies satisfactory to the Lessor, in the joint names of
               the Lessor and Lessee, and to pay the premiums therefor and to
               deliver said policies or certificates thereof, unto the Lessor,
               and the failure of the Lessee either to effect said insurance in
               the names here called for or to pay the premiums therefor or to
               deliver said policies, or certificates, thereof, unto the Lessor
               shall permit the Lessor to effect said insurance and to pay the
               requisite premiums therefor, which premiums shall be repayable un
               him with the next installment of rental, and failure to repay the
               same shall carry with it the same consequence as failure to pay
               any installment of rental. Each insurer mentioned in this
               paragraph shall agree, by endorsement upon the policy or policies
               issued by it, or by independent instrument furnished to the
               Lessor, that it will give the Lessor 30 days written notice
               before the policy or policies in question shall be altered or
               cancelled.

NOTICE              24. Whenever it is required that any notice be given
               hereunder, the same shall be sufficiently served by depositing
               the same in the United States Mail, postage prepaid, and
               addressed to the addresses set forth below:

                    To Lessor at:  44 Montgomery Street
                                   San Francisco, California 94104

                    To Lessee at:   2495 Estand Way
                                    Pleasant Hill, CA 94522

               or to such other addresses as a party may designate by written
               notice to the other party in the manner herein provided.


LESSOR'S            25. The term "Lessor", as used in this Paragraph, shall mean
LIABILITY      only the owner or owners at the time in question of the fee title
               or its interest in a ground lease of the Premises, and in the
               event of any transfer of such title or interest, Lessor herein
               named (and in case of any subsequent transfers the then grantor)
               shall be relieved from and after the date of such transfer of all
               liability as respects Lessor's obligations thereafter to be
               performed, provided that any funds in the hands Lessor or the
               then grantor at the time of such transfer, in which Lessee has an
               interest, shall be delivered to the grant. The obligations
               contained in this Lease to be performed by Lessor shall be
               binding on Lessor's Successors and assigns only during their
               respective periods of ownership.

WAIVER              26. The waiver by Lessor of any breach of any term, covenant
               or condition herein contained shall not be deemed be a waiver of
               Such term. covenant or condition or any subsequent breach of the
               same or any other term, covenant condition therein contained. The
               subsequent acceptance of rent hereunder by Lessor shall not be
               deemed to be a wavier of any preceding breach by Lessee of any
               term, covenant or condition of this lease, other than the failure
               of Lessee to ??? the particular rental so accepted, regardless of
               Lessors knowledge of such preceding breach at the time of
               acceptance such rent.

 
HOLD OVER           27. Any holding over after the expiration of the said term,
               with the consent of Lessor, shall be construed to be a tenancy
               from month to month, at a rental in the amount of the last
               monthly rental plus all other charges payable hereunder, and
               shall otherwise be on the terms and conditions herein specified,
               so far as applicable.

SUCCESSORS           28. The covenants and conditions herein contained shall,
               subject to the provisions as to assignment, apply to and bind the
               heirs, successors, executors, administrators and assigns of all
               of the parties hereto; and all of the parties hereto shall be
               jointly and severally liable hereunder.

TIME                29. Time is of the essence of this lease.

CAPTIONS            30. The captions in the margins of this lease are for
               convenience only and are not a part of this lease and do not in
               any way limit or amplify the terms and provisions of this lease.

SUBORDINATION       31. The Lessee covenants that this lease is and at all times
               shall be subject and subordinate to the lien of any mortgage or
               deed of trust now existing or which the Lessor or any subsequent
               owner of the demised premises shall make covering said demised
               premises or the building of which said premiums are a part, and
               to any and all advances made or to be made under or upon said
               mortgage or deed of trust, and to the interest thereon.
               Notwithstanding such subordination Lessee's right to quiet
               possession of the premises shall not be disturbed if Lessee is
               not in default hereunder and so long as Lessee shall pay the rent
               and observe and perform all of the provisions of this lease.

ESTOPPEL            32. Lessee shall at any time and from time to time upon not
CERTIFICATE    less than ten (10) days prior written notice from Lessor execute,
               acknowledge and deliver to Lessor a statement in writing (i)
               certifying that this Lease is unmodified and in full force and
               effect (or, if modified stating the nature of such modification
               and certifying that this Lease as so modified, is in full force
               and effect) and the dates to which the rental and other charges
               are paid in advance, if any, and (ii) acknowledging that there
               are not, to Lessee's knowledge, any uncured defaults on the part
               of Lessor hereunder, or specifying such defaults if any are
               claimed. Any such statement may be relied upon by any prospective
               purchaser or encumbrancer of all or any portion of the real
               property of which the premises are a part. Lessee s failure to
               deliver such statement within such time shall be conclusive upon
               Lessee (i) that this Lease is in full force and effect, without
               modification except as may be represented by Lessor, (ii) that
               there are no uncured defaults in Lessor's performance, and (iii)
               that not more than one month's rental has been paid in advance

SPECIAL             33. Special provisions of this Lease numbered --------34
PROVISIONS     ---------through ----------40--------are attached hereto and are
               made a part hereof.

               34. All base rent, additional rent and all other sums which may
               from time to time become due and payable by Lessee to Lessor
               under any of the provisions of this Lease shall bear interest
               from and after the due date thereof at the greater of ten percent
               (10%), or the maximum rate of interest permitted by law.

               35. During the full term of this Lease, Lessee shall carry, at
               its expense, insurance against loss and damage by fire with an
               "All Risk" endorsement for the full insurable value of Lessee's s
               merchandise, trade fixtures, furnishings, operating equipment and
               personal property, including wall coverings, carpeting and
               drapes, if installed by Lessee.


                 IN WITNESS WHEREOF, the parties hereto have executed this lease
               the day and year first above written.

                   LESSORS                                LESSEES

PLEASANT HILL INDUSTRIAL PARK                   TUTSYSTEMS, INC.  
ASSOCIATES, A CALIFORNIA LIMITED                
PARTNERSHIP                                     BY:/S/ MICHAEL SULLIVAN, V.P.
- -------------------------------------           ------------------------------- 
LOWENBERG HOLDINGS, GENERAL PARTNER
WILLIAM J. LOWENBERG, ITS PRESIDENT
- --------------------------------------          --------------------------------

- --------------------------------------          --------------------------------



     This lease has been prepared for submission to your attorney for his
approval. No representation or recommendation is made by Lowenberg Realty
Company, or its agents or employees as to the legal sufficiency, legal effect,
or tax consequences of this lease or the transaction relating thereto.

 
               36. Lessee warrants that it shall not make any use of the
               Premises which may cause contamination of the building and
               improvements, the soil or ground water and hereby indemnifies and
               agrees to hold Lessor harmless from any claim for damages arising
               from any contamination caused by Lessee's use Of the Premises
               including, but not limited to, damage to Lessor's property, the
               property of any third party or personal injury to any person, and
               any attorneys' fees in connection with any actions which may
               arise from any contamination caused by, Lessee or Lessee's
               agents. The indemnification given hereunder shall be continuing
               and shall survive the termination of the Lease term.

               37. Provided Lessee has satisfactorily performed all terms and
               conditions of this Lease, Lessee shall have the option to extend
               this Lease for one additional consecutive two-year term, at a
               rental to be based on the Consumer Price Index and in accordance
               with Paragraph 22 of the herein Lease.

                    Lessee to provide Lessor written notice of its intention to
               exercise this option on or before 90 days prior to the expiration
               of the initial term of this Lease.

               38. If Lessee does not exercise the option to renew as per
               Paragraph 37 of this Lease, then Lessee shall pay and deliver to
               Lessor on or before the last day of this Lease a check in the
               amount of $10,000 for unamortized tenant improvements.

               39. Lessor agrees to grant to Lessee a First Right of Refusal on
               approximately 5000 square feet currently vacant (adjacent to
               their existing space).

               Lessee agrees to take this space on an "as is" basis, at a rate
               of 65c per square foot per month.

               If Lessee, within 3 calendar days after receipt of Lessor's
               notice, indicates in writing its agreement to lease the spaces
               the space shall be included within the premises and leased to
               the. Lessee pursuant to the provisions of this Lease. However,
               the rent payable under this lease shall be increased by the
               amount of rent attributed to the additional space leased by
               Lessee. The parties shall immediately execute an amendment to he
               Lease stating the addition of the expansion space, to the
               premises.

               If the Lessee does not indicate within three calendar days its
               agreement to lease the additional space, Lessor thereafter shall
               have the right to lease the space to a third party, and this
               option to expand premises shall be of no further force and
               effect.


               40. Each Option granted to Lessee in this Lease is personal to
               Lessee and may not be exercised or be assigned voluntarily or
               involuntarily, by or to any person or entity other than Lessee.

                                      -7-

 
                              EXTENSION OF LEASE
                              ------------------

This EXTENSION OF LEASE made this 3rd day of March, 1998, by and between
PLEASANT HILL INDUSTRIAL PARK ASSOCIATES, A CALIFORNIA LIMITED PARTNERSHIP,
LESSOR, AND TUTSYSTEMS, INC., LESSEE herein after respectively called "Lessor"
and "Lessee".

                                  WITNESSETH

1.   On April 4, 1995 a Lease was executed and on November 11, 1998 an Amendment
     to Lease was executed by and between PLEASANT HILL INDUSTRIAL PARK
     ASSOCIATES, A CALIFORNIA LIMITED PARTNERSHIP, Lessor, and TUTSYSTEMS, INC.,
     Lessee, for those certain premises commonly known and desigated as 2495
     Estand Way, Pleasant Hill, CA.

2.   The parties do hereby agree to:

     a.  Extend the term of the Lease three years from June 1, 1998 to May 31, 
         2001.

     b.  The monthly rental shall be payable as follows to LOWENBERG
         CORPORATION: The sum of SEVENTEEN THOUSAND TWO HUNDRED SEVENTY-FOUR AND
         80/100 ($17,274.80) DOLLARS commencing on the first day of June, 1998
         and continuing on the first day of each and every month thereafter to
         and including the first day of November, 1999; thereafter, the sum of
         EIGHTEEN THOUSAND FOUR HUNDRED ELEVEN AND 30/100 ($18,411.30) DOLLARS
         commencing the first day of December 1999 and continuing on the first
         day of each and every month thereafter to and including the first day
         of May 2001. As additional rent Lessee agrees to pay $200 per month for
         water.

     c.  Provided Lessee has satisfactorily performed all terms and conditions
         of this Lease, Lessee shall have the option to extend this Lease for
         one additional consecutive two (2) year term at a rental rate to be
         negotiated. Lessee to provide Lessor written notice of its intention to
         exercise this option on or before 120 days prior to the expiration of
         the initial term of this Lease.

     d.  Each Option granted to Lessee in this Lease are personal to Lessee and
         may not be exercised or be assigned voluntarily or involuntarily, by or
         to any person or entity other than Lessee.


3.   All other terms and conditions of the above Lease shall remain the same.

IN WITNESS WHEREOF, the undersigned "Lessor" and "Lessee" have executed these 
presents the day and year first above mentioned.

Lessor:  PLEASANT HILL INDUSTRIAL PARK    LESSEE: TUTSYSTEMS, INC.
         ASSOCIATES, A CALIFORNIA
         LIMITED PARTNERSHIP

By /s/William J. Lowenberg                By /s/ Nelson B. Caldwell
   -----------------------------------       -----------------------------------
LOWENBERG HOLDINGS, GENERAL PARTNER
WILLIAM J. LOWENBERG, ITS PRESIDENT


 
                              AMENDMENT TO LEASE
                              ------------------                          

This AMENDMENT TO LEASE made this 11th day of November, 1996, by and between
PLEASANT HILL INDUSTRIAL PARK ASSOCIATES, A CALIFORNIA LIMITED PARTNERSHIP,
LESSOR, AND TUTSYSTEMS, INC., LESSEE herein after respectively called "Lessor"
and Lessee".


                                  WITNESSETH


1.   On April 4, 1995 a Lease was executed by and between PLEASANT HILL
     INDUSTRIAL PARK ASSOCIATES, A CALIFORNIA LIMITED PARTNERSHIP, lessor, and
     TUTSYSTEMS, INC., lessee, for those certain premises commonly known and
     designated as 2495 Estand Way, Pleasant Hill, CA.


2.   The parties do hereby agree to:


     a.   Increase the rentable square footage by 10,560 square feet as Lessee
          --------
          agrees to lease the adjacent space to the north of their current unit
          in addition to 2495 Estand Way, Pleasant Hill, California.  The new
          total square footage commencing January 1, 1997 is 22,730 square foot.

     b.   The monthly rental shall be payable as follows to LOWENBERG
          CORPORATION: The sum of SIXTEEN THOUSAND FIVE HUNDRED SEVENTY-NINE AND
          40/100 Dollars ($16,579.40) DOLLARS commencing on the first day of
          January, 1997 and continuing on the first day of each and every month
          thereafter to and including the first day of May, 1998.  As additional
          rent Lessee agrees to pay $150 per month for water.

     c.   Lessee shall deposit with Lessor upon execution hereof the sum of Six
          Thousand Three Hundred Fifty-Six and 15/100 ($6,356.15) Dollars
          payable to Lowenberg Corporation as additional security deposit making
          a new total of $16,579.40.

     d.   The Lessor, at its sole cost and expense shall complete the demolition
          in the expansion space and deliver the space in shell condition. Also
          the Lessor shall provide two five-ton HVAC units as per plans dated
          October 25, 1996 by Craig Hudson.  These units were specified as per
          Title 24.

     e.   Provided Lessee has satisfactorily performed all terms and conditions
          of this Lease, Lessee shall have the option to extend this Lease for
          one additional consecutive 18 month term at a rental rate of 76c per
          square foot per month. Lessee to provide Lessor written notice of its
          intention to exercise this option on or before 120 days prior to the
          expiration of the initial term of this Lease.

     f.   Paragraphs 8, 14 and 21 of the Lease dated April 4, 1995 shall be
          amended to reflect this increase in square footage by increasing
          Lessee's percentage of occupancy and prorate share to 22.7% of all
          expenses outlined in the paragraphs above.

 
3.   Lessor and Lessee further agree to delete Paragraphs 22, 37, and 39 of the
     Lease dated April 4, 1995. It is further understood and agreed that
     Paragraph 38 of said Lease now applies solely to Paragraph 2e of this
     Amendment to Lease.


4.   All other terms and conditions of the above Lease shall remain the same.

IN WITNESS WHEREOF, the undersigned "Lessor" and "Lessee" have executed these
presents the day and year first above mentioned.



LESSOR:  PLEASANT HILL INDUSTRIAL PARK            LESSEE:  TUTSYSTEMS, INC. 
         ASSOCIATES, A CALIFORNIA
         LIMITED PARTNERSHIP                        
 
 
BY /s/ [SIGNATURE ILLEGIBLE]^^                     BY /S/ Sean Laskey
  -------------------------------------             ---------------------------
LOWENBERG HOLDINGS, GENERAL PARTNER                  SEAN LASKEY
WILLIAM J. LOWENBERG, ITS PRESIDENT                  DIRECTOR OF OPERATIONS