PROMISSORY NOTE                      EXHIBIT 10.168

$825,000.00                                                   September 15, 2004


      FOR VALUE RECEIVED, on or before September 15, 2009 ("Maturity Date"), the
undersigned and if more than one, each of them, jointly and severally
(hereinafter referred to as "Borrower"), promises to pay to the order of BANK
ONE, NA, with its main office in Chicago, Illinois ("Bank") at its offices in
Tarrant County, Texas at 1301 S. Bowen Road, Suite 150, Arlington, Texas 76013,
the principal amount of EIGHT HUNDRED TWENTY-FIVE THOUSAND AND NO/100 DOLLARS
($825,000.00) ("Total Principal Amount"), or such amount less than the Total
Principal Amount which has been advanced to Borrower if the total amount
advanced under this Promissory Note ("Note") is less than the Total Principal
Amount, together with interest on such portion of the Total Principal Amount
which has been advanced to Borrower from the date advanced until paid at a
fluctuating rate per annum which shall from day to day be equal to the lesser of
(a) the Maximum Rate (as hereinafter defined), or (b) a rate ("Contract Rate"),
calculated on the basis of the actual days elapsed but computed as if each year
consisted of 360 days, equal to the sum of (i) the Prime Rate (as hereinafter
defined), plus (ii) one-fourth percent (.25%); provided, however, that if at any
time the Contract Rate shall exceed the Maximum Rate, thereby causing the
interest on this Note to be limited to the Maximum Rate, then any subsequent
reduction in the Prime Rate shall not reduce the rate of interest on this Note
below the Maximum Rate until the total amount of interest accrued on this Note
equals the amount of interest which would have accrued on this Note if the
Contract Rate had at all times been in effect.

      The term "Maximum Rate," as used herein, shall mean at the particular time
in question the maximum rate of interest which, under applicable law, may then
be charged on this Note. If such maximum rate of interest changes after the date
hereof and this Note provides for a fluctuating rate of interest, the Maximum
Rate shall be automatically increased or decreased, as the case may be, without
notice to Borrower from time to time as of the effective date of each change in
such Maximum Rate. If applicable law ceases to provide for such a maximum rate
of interest, the Maximum Rate shall be equal to eighteen percent (18%) per
annum.

      The term Prime Rate, as used herein, shall mean a rate per annum equal to
the prime rate of interest announced from time to time by Bank One, NA or its
parent (which is not necessarily the lowest rate charged to any customer),
changing when and as said prime rate changes, each change in the rate to be
charged on this Note to become effective without notice to Borrower on the
effective date of each change in the Maximum Rate or the Prime Rate, as the case
may be.

      Interest on this Note is computed by applying the ratio of the annual
interest rate over a year of 360 days, multiplied by the outstanding principal
balance, multiplied by the actual number of days the principal balance is
outstanding.

      The principal of and all accrued but unpaid interest on this Note shall be
due and payable without offset or reduction as follows:

      (a)   Principal and interest shall be amortized on the basis of a fifteen
            (15) year term payable in monthly installments of principal and
            interest in the amount of Six Thousand, Four Hundred Seventeen and
            11/100 Dollars ($6,417.11) commencing on October 15, 2004, and
            continuing on the 15th day of each month thereafter through
            September 15, 2005. Interest shall be adjusted with each change in
            the Prime Rate. Each such payment shall be applied first to accrued
            but unpaid interest and then to principal. Commencing on October
            15th of each year beginning in 2005, the monthly principal and
            interest installments thereafter due and payable shall be adjusted
            annually based on the remaining portion of the fifteen (15) year
            amortization period and the Prime Rate in effect on the 15th day of
            the preceding September, plus one-fourth percent (.25%). In the
            event the Prime Rate shall increase to a rate such that the monthly
            payment of principal and interest then payable shall not be
            sufficient to equal the total unpaid interest accrued to such
            payment date, then Borrower shall pay monthly an amount equal to the
            interest due on such payment date.

      (b)   The outstanding principal balance of this Note, together with all
            accrued but unpaid interest, shall be due and payable on the
            Maturity Date.

      If a payment is ten (10) or more days late, Borrower will pay a
delinquency charge in an amount equal to the greater of (i) $25.00, or (ii) 5.0%
of the amount of the delinquent payment up to the maximum amount of $1,500.00
per late charge. Upon default, including failure to pay upon final maturity,
Bank, at its option, may also, if permitted under applicable law, do one or both
of the following: (a) increase the applicable interest rate on this Note three
(3.00) percentage points, and (b) add any unpaid accrued interest to principal
and such sum will bear interest therefrom until paid at the rate provided in
this Note (including any increased rate). The interest rate will not exceed the
maximum rate permitted by applicable law.

      Borrower may from time to time prepay all or any portion of the principal
of this Note without premium or penalty. Unless otherwise agreed to in writing,
or otherwise required by applicable law, payments will be applied first to
unpaid accrued interest, then to principal, and any remaining amount to any
unpaid collection costs, late charges and other charges; provided, however, upon
delinquency or other default, Bank reserves the right to apply payments among
principal, interest, late charges, collection costs and other charges, at its
discretion. All prepayments shall be applied to the indebtedness owing hereunder
in such order and manner as Bank may from time to time determine in its sole
discretion. All payments and prepayments of principal of or interest on this
Note shall be made in lawful money of the United States of America in
immediately available funds, at the address of Bank indicated above, or such
other place as the holder of this Note shall designate in writing to Borrower.
If any payment of principal of or interest on this Note shall become due on a
day which is not a Business Day (as hereinafter defined), such payment shall be
made on the next succeeding Business Day and any such extension of time shall be
included in computing interest in connection with such payment. As used herein,
the term "Business Day" shall mean any day other than a Saturday, Sunday or any
other day on which national banking associations are authorized to be closed.
The books and records of Bank shall be prima facie evidence of all outstanding
principal of and accrued and unpaid interest on this Note.

      This Note has been executed and delivered pursuant to that certain Loan
Agreement dated December 31, 2003 by and between Borrower and Bank ("Loan
Agreement"), and is secured by, inter alia,a Deed of Trust, Security Agreement
and Assignment of Rents and Leases of even date herewith from Borrower in favor
of Douglass J. Kroiss, Trustee for the benefit of the Bank, covering certain
real property situated in Dallas County, Texas, as more particularly described
therein.

      This Note, the Loan Agreement and all other documents evidencing,
securing, governing, guaranteeing and/or pertaining to this Note, including but
not limited to those documents described above, are hereinafter collectively
referred to as the "Loan Documents." The holder of this Note is entitled to the
benefits and security provided in the Loan Documents.

PROMISSORY NOTE

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      Borrower agrees that no advances under this Note shall be used for
personal, family or household purposes, and that all advances hereunder shall be
used solely for business, commercial, investment, or other similar purposes.

      Borrower agrees that upon the occurrence of any one or more of the
following events of default ("Event of Default"):

      (a)   failure of Borrower to pay any installment of principal of or
            interest on this Note or on any other indebtedness of Borrower to
            Bank when due; or

      (b)   the occurrence of any event of default specified in any of the other
            Loan Documents; or

      (c)   the bankruptcy or insolvency of, the assignment for the benefit of
            creditors by, or the appointment of a receiver for any of the
            property of, or the liquidation, termination, dissolution or death
            or legal incapacity of, any party liable for the payment of this
            Note, whether as maker, endorser, guarantor, surety or otherwise;

the holder of this Note may, at its option, without further notice or demand,
(i) declare the outstanding principal balance of and accrued but unpaid interest
on this Note at once due and payable, (ii) refuse to advance any additional
amounts under this Note, (iii) foreclose all liens securing payment hereof, (iv)
pursue any and all other rights, remedies and recourses available to the holder
hereof, including but not limited to any such rights, remedies or recourses
under the Loan Documents, at law or in equity, or (v) pursue any combination of
the foregoing.

      The failure to exercise the option to accelerate the maturity of this Note
or any other right, remedy or recourse available to the holder hereof upon the
occurrence of an Event of Default hereunder shall not constitute a waiver of the
right of the holder of this Note to exercise the same at that time or at any
subsequent time with respect to such Event of Default or any other Event of
Default. The rights, remedies and recourses of the holder hereof, as provided in
this Note and in any of the other Loan Documents, shall be cumulative and
concurrent and may be pursued separately, successively or together as often as
occasion therefore shall arise, at the sole discretion of the holder hereof. The
acceptance by the holder hereof of any payment under this Note which is less
than the payment in full of all amounts due and payable at the time of such
payment shall not (i) constitute a waiver of or impair, reduce, release or
extinguish any right, remedy or recourse of the holder hereof, or nullify any
prior exercise of any such right, remedy or recourse, or (ii) impair, reduce,
release or extinguish the obligations of any party liable under any of the Loan
Documents as originally provided herein or therein.

      This Note and all of the other Loan Documents are intended to be performed
in accordance with, and only to the extent permitted by, all applicable usury
laws. If any provision hereof or of any of the other Loan Documents or the
application thereof to any person or circumstance shall, for any reason and to
any extent, be invalid or unenforceable, neither the application of such
provision to any other person or circumstance nor the remainder of the
instrument in which such provision is contained shall be affected thereby and
shall be enforced to the greatest extent permitted by law. It is expressly
stipulated and agreed to be the intent of the holder hereof to at all times
comply with the usury and other applicable laws now or hereafter governing the
interest payable on the indebtedness evidenced by this Note. If the applicable
law is ever revised, repealed or judicially interpreted so as to render usurious
any amount called for under this Note or under any of the other Loan Documents,
or contracted for, charged, taken, reserved or received with respect to the
indebtedness evidenced by this Note, or if Bank's exercise of the option to
accelerate the maturity of this Note, or if any prepayment by Borrower results
in Borrower having paid any interest in excess of that permitted by law, then it
is the express intent of Borrower and Bank that all excess amounts theretofore
collected by Bank be credited on the principal balance of this Note (or, if this
Note and all other indebtedness arising under or pursuant to the other Loan
Documents have been paid in full, refunded to Borrower), and the provisions of
this Note and the other Loan Documents immediately be deemed reformed and the
amounts thereafter collectable hereunder and thereunder reduced, without the
necessity of the execution of any new document, so as to comply with the then
applicable law, but so as to permit the recovery of the fullest amount otherwise
called for hereunder or thereunder. All sums paid, or agreed to be paid, by
Borrower for the use, forbearance, detention, taking, charging, receiving or
reserving of the indebtedness of Borrower to Bank under this Note or arising
under or pursuant to the other Loan Documents shall, to the maximum extent
permitted by applicable law, be amortized, prorated, allocated and spread
throughout the full term of such indebtedness until payment in full so that the
rate or amount of interest on account of such indebtedness does not exceed the
usury ceiling from time to time in effect and applicable to such indebtedness
for so long as such indebtedness is outstanding. To the extent federal law
permits Bank to contract for, charge or receive a greater amount of interest,
Bank will rely on federal law instead of the Texas Finance Code, as
supplemented, for the purpose of determining the Maximum Rate. Additionally, to
the maximum extent permitted by applicable law now or hereafter in effect, Bank
may, at its option and from time to time, implement any other method of
computing the Maximum Rate under the Texas Finance Code, as supplemented, or
under other applicable law, by giving notice, if required, to Borrower as
provided by applicable law now or hereafter in effect. Notwithstanding anything
to the contrary contained herein or in any of the other Loan Documents, it is
not the intention of Bank to accelerate the maturity of any interest that has
not accrued at the time of such acceleration or to collect unearned interest at
the time of such acceleration.

      In no event shall Chapter 346 of the Texas Finance Code (which regulates
certain revolving loan accounts and revolving tri-party accounts) apply to this
Note. To the extent that Chapter 303 of the Texas Finance Code, is applicable to
this Note, the "weekly ceiling" specified in such Chapter 303 is the applicable
ceiling; provided that, if any applicable law permits greater interest, the law
permitting the greatest interest shall apply.

      If this Note is placed in the hands of an attorney for collection, or is
collected in whole or in part by suit or through probate, bankruptcy or other
legal proceedings of any kind, Borrower agrees to pay, in addition to all other
sums payable hereunder, all costs and expenses of collection, including but not
limited to reasonable attorneys' fees.

      Borrower and any and all endorsers and guarantors of this Note severally
waive presentment for payment, notice of nonpayment, protest, demand, notice of
protest, notice of intent to accelerate, notice of acceleration and dishonor,
diligence in enforcement and indulgences of every kind and without further
notice hereby agree to renewals, extensions, exchanges or releases of
collateral, taking of additional collateral, indulgences or partial payments,
either before or after maturity.

      Borrower agrees that Bank may provide any information Bank may have about
Borrower or about any matter relating to this Note to BANK ONE CORPORATION, or
any of its subsidiaries or affiliates or their successors, or to any one or more
purchasers or potential purchasers of this Note. Borrower agrees that Bank may
at any time sell, assign or transfer one of more interests or participations in
all or any part of its rights or obligations in this Note to one or more
purchases whether or not related to Bank.

      BORROWER AND BANK (BY ITS ACCEPTANCE HEREOF) HEREBY VOLUNTARILY,
KNOWINGLY, IRREVOCABLY AND UNCONDITIONALLY WAIVE ANY RIGHT TO HAVE A JURY
PARTICIPATE IN RESOLVING ANY DISPUTE (WHETHER BASED UPON CONTRACT, TORT OR
OTHERWISE) BETWEEN BORROWER AND BANK ARISING OUT OF OR IN ANY WAY RELATED TO
THIS NOTE OR THE TRANSACTIONS CONTEMPLATED BY THIS NOTE. THIS PROVISION IS A
MATERIAL INDUCEMENT TO BANK TO PROVIDE THE FINANCING EVIDENCED BY THIS NOTE.

PROMISSORY NOTE

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      THIS NOTE HAS BEEN EXECUTED UNDER, AND SHALL BE CONSTRUED AND ENFORCED IN
ACCORDANCE WITH, THE LAWS OF THE STATE OF TEXAS, EXCEPT AS SUCH LAWS ARE
PREEMPTED BY APPLICABLE FEDERAL LAWS.

                                          BORROWER:

                                          MACE SECURITY PRODUCTS, INC.

                                          By: /s/ Gregory M. Krzemien
                                              -----------------------
                                          Gregory M. Krzemien, Treasurer

PROMISSORY NOTE

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