Exhibit 4
                         INSTRUMENT SYSTEMS CORPORATION
                             1995 STOCK OPTION PLAN

SECTION 1. GENERAL PROVISIONS

1.1 NAME AND GENERAL PURPOSE

     The name of this plan is the Instrument Systems Corporation 1995 Stock
Option Plan (hereinafter called the "Plan"). The purpose of the Plan is to
enable Instrument Systems Corporation (the "Company") and its subsidiaries and
affiliates to foster and promote the interests of the Company by attracting and
retaining officers and employees of the Company who contribute to the Company's
success by their ability, ingenuity and industry, to enable such officers and
employees of the Company to participate in the long-term success and growth of
the Company by giving them a proprietary interest in the Company and to provide
incentive compensation opportunities competitive with those of competing
corporations.

1.2 DEFINITIONS

    a.  "Affiliate" means any person or entity controlled by or under common
        control with the Company, by virtue of the ownership of voting
        securities, by contract or otherwise.

    b.  "Board" means the Board of Directors of the Company.

    c.  "Change in Control" means a change of control of the Company, or in any
        person directly or indirectly controlling the Company, which shall mean:

        (a) a change in control as such term is presently defined in Regulation
        240.12b-(f) under the Securities Exchange Act of 1934, as amended (the
        "Exchange Act"); or

        (b) if any "person" (as such term is used in Section 13(d) and 14(d) of
        the Exchange Act) other than the Company or any "person" who on the date
        of this Agreement is a director or officer of the Company, becomes the
        "beneficial owner" (as defined in Rule 13(d)-3 under the Exchange Act)
        directly or indirectly, of securities of the Company representing twenty
        percent (20%) or more of the voting power of the Company's then
        outstanding securities; or

        (c) if during any period of two (2) consecutive years during the term of
        this Plan, individuals who at the beginning of such period constitute
        the Board of Directors, cease for any reason to constitute at least a
        majority thereof.

    d.  "Code" means the Internal Revenue Code of 1986, as amended.

    e.  "Committee" means the Committee referred to in Section 1.3 of the Plan.

    f.  "Common Stock" means shares of the Common Stock, par value $.25 per
        share, of the Company.

    g.  "Company" means Instrument Systems Corporation, a corporation organized
        under the laws of the State of Delaware (or any successor corporation).

    h.  "Disinterested Person" shall have the meaning set forth in Rule
        16b-3(c)(2) as promulgated by the Securities and Exchange Commission
        (the "Commission"); provided, that such person is also an "outside
        director" as set forth in Section 162(m) of the Code and the regulations
        promulgated thereunder.

    i.  "Fair Market Value" means the market price of the Common Stock on the
        New York Stock Exchange consolidated reporting system on the date of the
        grant or on any other date on which the Common Stock is to be valued
        hereunder. If no sale shall have been reported on the New York Stock
        Exchange consolidated reporting system on such date, Fair Market Value
        shall be determined by the Committee in accordance with the Treasury
        Regulations applicable to incentive stock options under Section 422 of
        the Code.

     j. "Incentive Stock Option" means an Incentive Stock Option as described
        in Section 2.1 of the Plan.

     k. "Non-Qualified Stock Option" means a Non-Qualified Stock Option as
        described in Section 2.1 of the Plan.


     l. "Option" means any option to purchase Common Stock under Section 2 of
        the Plan.


     m. "Participant" means any officer or employee of the Company, a Subsidiary
        or an Affiliate who is selected by the Committee to participate in the
        Plan.

     n. "Subsidiary" means any corporation in which the Company possesses
        directly or indirectly 50% or more of the combined voting power of all
        classes of stock of such corporation.

     o. "Total Disability" means accidental bodily injury or sickness which
        wholly and continuously disabled an optionee. The Committee, whose
        decisions shall be final, shall make a determination of Total
        Disability.

1.3 ADMINISTRATION OF THE PLAN

     The Plan shall be administered by the Committee appointed by the Board
consisting of two or more members of the Board all of who shall be Disinterested
Persons. The Committee shall serve at the pleasure of the Board and shall have
such powers as the Board may, from time to time, confer upon it.

     Subject to this Section 1.3, the Committee shall have sole and complete
authority to adopt, alter, amend or revoke such administrative rules, guidelines
and practices governing the operation of the Plan as it shall, from time to
time, deem advisable, and to interpret the terms and provisions of the Plan.

     The Committee shall keep minutes of its meetings and of action taken by it
without a meeting. A majority of the Committee shall constitute a quorum, and
the acts of a majority of the members present at any meeting at which a quorum
is present, or acts approved in writing by all of the members of the Committee
without a meeting, shall constitute the acts of the Committee.

1.4 ELIGIBILITY

     Stock options may be granted only to officers or employees of the Company
or a Subsidiary or Affiliate. Subject to Section 2.3, any person who has been
granted any Option may, if he is otherwise eligible, be granted an additional
Option or Options.

1.5 SHARES

     The aggregate number of shares reserved for issuance pursuant to the Plan
shall be 1,000,000 shares of Common Stock, or the number and kind of shares of
stock or other securities which shall be substituted for such shares or to which
such shares shall be adjusted as provided in Section 1.6. No individual may be
granted options to purchase more than an aggregate of 500,000 shares of Common
Stock pursuant to the Plan.

     Such number of shares may be set aside out of the authorized but unissued
shares of Common Stock or out of issued shares of Common Stock acquired for and
held in the Treasury of the Company, not reserved for any other purpose. Shares
subject to, but not sold or issued under, any Option terminating or expiring for
any reason prior to its exercise in full will again be available for Options
thereafter granted during the balance of the term of the Plan.

1.6 ADJUSTMENTS DUE TO STOCK SPLITS, MERGERS, CONSOLIDATION, ETC.

     If, at any time, the Company shall take any action, whether by stock
dividend, stock split, combination of shares or otherwise, which results in a
proportionate increase or decrease in the number of shares of Common Stock
theretofore issued and outstanding, the number of shares which are reserved for
issuance under the Plan and the number of shares which, at such time, are
subject to Options shall, to the extent deemed appropriate by the Committee, be
increased or decreased in the same proportion, provided, however, that the
Company shall not be obligated to issue fractional shares.

     Likewise, in the event of any change in the outstanding shares of Common
Stock by reason of any recapitalization, merger, consolidation, reorganization,
combination or exchange of shares or other corporate change, the Committee shall
make such substitution or adjustments, if any, as it deems to be appropriate, as
to the number or kind of shares of Common Stock or other securities which are
reserved for issuance under the Plan and the number of shares or other
securities which, at such time are subject to Options.


     In the event of a Change in Control, at the option of the Board or the
Committee, (a) all options outstanding on the date of such Change in Control
shall, for a period of sixty (60) days following such Change in Control, become
immediately and fully exercisable, and (b) an optionee will be permitted to
surrender for cancellation within sixty (60) days after such Change in Control
any option or portion of an option which was granted more than six (6) months
prior to the date of such surrender, to the extent not yet exercised, and to
receive a cash payment in an amount equal to the excess, if any, of the Fair
Market Value (on the date of surrender) of the shares of Common Stock subject to
the option or portion thereof surrendered, over the aggregate purchase price for
such Shares under the option.


1.7 NON-ALIENATION OF BENEFITS

     Except as herein specifically provided, no right or unpaid benefit under
the Plan shall be subject to alienation, assignment, pledge or charge and any
attempt to alienate, assign, pledge or charge the same shall be void. If any
Participant or other person entitled to benefits hereunder should attempt to
alienate, assign, pledge or charge any benefit hereunder, then such benefit
shall, in the discretion of the Committee, cease.

1.8 WITHHOLDING OR DEDUCTION FOR TAXES

     If, at any time, the Company or any Subsidiary or Affiliate is required,
under applicable laws and regulations, to withhold, or to make any deduction for
any taxes, or take any other action in connection with any Option exercise, the
Participant shall be required to pay to the Company or such Subsidiary or
Affiliate, the amount of any taxes required to be withheld, or, in lieu thereof,
at the option of the Company, the Company or such Subsidiary or Affiliate may
accept a sufficient number of shares of Common Stock to cover the amount
required to be withheld.

1.9 ADMINISTRATIVE EXPENSES

     The entire expense of administering the Plan shall be borne by the Company.

1.10 GENERAL CONDITIONS

     a. The Board or the Committee may, from time to time, amend, suspend or
        terminate any or all of the provisions of the Plan, provided that,
        without the Participant's approval, no change may be made which would
        prevent an Incentive Stock Option granted under the Plan from qualifying
        as an Incentive Stock Option under Section 422 of the Code or result in
        a "modification" of the Incentive Stock Option under Section 424(h) of
        the Code or otherwise alter or impair any right theretofore granted to
        any Participant ; and further provided that, without the consent and
        approval of the holders of a majority of the outstanding shares of
        Common Stock of the Company present at a meeting at which a quorum
        exists, neither the Board nor the Committee may make any amendment which
        (i) changes the class of persons eligible for options; (ii) increases
        (except as provided under Section 1.6 above) the total number of shares
        or other securities reserved for issuance under the Plan; (iii)
        decreases the minimum option prices stated in Section 2.2 hereof (other
        than to change the manner of determining Fair Market Value to conform to
        any then applicable provision of the Code or any regulation thereunder);
        (iv) extends the expiration date of the Plan, or the limit on the
        maximum term of Options; or (v) withdraws the administration of the Plan
        from a committee consisting of two or more members, each of whom is a
        Disinterested Person.

     b. With the consent of the Participant affected thereby, the Committee may
        amend or modify any outstanding Option in any manner not inconsistent
        with the terms of the Plan, including, without limitation, and
        irrespective of the provisions of Sections 2.3(c) and 2.4(b) below, to
        accelerate the date or dates as of which an installment of an Option
        becomes exercisable.

     c. Nothing contained in the Plan shall prohibit the Company or any
        Subsidiary or Affiliate from establishing other additional incentive
        compensation arrangements for employees of the Company or such
        Subsidiary
        or Affiliate.

     d. Nothing in the Plan shall be deemed to limit, in any way, the right of
        the Company or any Subsidiary or Affiliate to terminate a Participant's
        employment with the Company (or such Subsidiary or Affiliate) at any
        time.

     e. Any decision or action taken by the Board or the Committee arising out
        of or in connection with the construction, administration,
        interpretation and effect of the Plan shall be conclusive and binding
        upon all Participants and any person claiming under or through any
        Participant.

     f. No member of the Board or of the Committee shall be liable for any act
        or action, whether of commission or omission, (i) by such member except
        in circumstances involving actual bad faith, nor (ii) by any other
        member or by any officer, agent or employee.

1.11 COMPLIANCE WITH APPLICABLE LAW

     Notwithstanding any other provision of the Plan, the Company shall not be
obligated to issue any shares of Common Stock, or grant any Option with respect
thereto, unless it is advised by counsel of its selection that it may do so
without violation of the applicable Federal and State laws pertaining to the
issuance of securities and the Company may require any stock certificate so
issued to bear a legend, may give its transfer agent instructions limiting the
transfer thereof, and may take such other steps, as in its judgment are
reasonably required to prevent any such violation.

1.12 EFFECTIVE DATES

     The Plan was adopted by the Board on November 8, 1994, subject to approval
by the stockholders of the Company. The Plan shall terminate on November 7,
2004.

SECTION 2. OPTION GRANTS

2.1 AUTHORITY OF COMMITTEE

     Subject to the provisions of the Plan, the Committee shall have the sole
and complete authority to determine (i) the Participants to whom Options shall
be granted; (ii) the number of shares to be covered by each Option; and (iii)
the conditions and limitations, if any, in addition to those set forth in
Sections 2 and 3 hereof, applicable to the exercise of an Option, including
without limitation, the nature and duration of the restrictions, if any, to be
imposed upon the sale or other disposition of shares acquired upon exercise of
an Option.

     Stock options granted under the Plan may be of two types: an incentive
stock option ("Incentive Stock Option"); and a non-qualified stock option
("Non-Qualified Stock Option").

     It is intended that the Incentive Stock Options granted hereunder shall
constitute incentive stock options within the meaning of Section 422 of the Code
and shall be subject to the tax treatment described in Section 422 of the Code.

     Anything in the Plan to the contrary notwithstanding, no provision of the
Plan relating to Incentive Stock Options shall be interpreted, amended or
altered, nor shall any discretion or authority granted under the Plan be so
exercised, so as to disqualify either the Plan or, without the consent of the
optionee, any Incentive Stock Option under Section 422 of the Code.

     The Committee shall have the authority to grant Incentive Stock Options, or
to grant Non-Qualified Stock Options, or to grant both types of Options. To the
extent that any Option does not qualify as an Incentive Stock Option, in whole
or in part, it shall constitute a separate Non-Qualified Stock Option to the
extent of such disqualification.

2.2 OPTION EXERCISE PRICE

     The price of stock purchased upon the exercise of Options granted pursuant
to the Plan shall be the Fair Market Value thereof at the time that the Option
is granted.

     If an employee owns or is deemed to own (by reason of the attribution rules
applicable under Section 424(d) of the Code) more than 10% of the combined
voting power of all classes of the stock of the Company or any parent
corporation of the Company or Subsidiary and an Option granted to such employee
is intended to qualify as an Incentive Stock Option within the meaning of
Section 422 of the Code, the exercise price shall be no less than 110% of the
Fair Market Value of the Common Stock on the date the Option is granted. The
purchase price is to be paid in full in cash, certified or bank cashier's check
or, at the option of the Company, Common Stock valued at its Fair Market Value
on the date of exercise, or a combination thereof, when the Option is exercised
and stock certificates will be delivered only against such payment.

2.3 INCENTIVE STOCK OPTION GRANTS

     Each Incentive Stock Option will be subject to the following provisions:

     a. Term of Option

        An Incentive Stock Option will be for a term of not more than ten years
        from the date of grant, except in the case of an employee described in
        the second paragraph of Section 2.2 above in which case an Incentive
        Stock Option will be for a term of not more than five years from the
        date of the grant.

     b. Annual Limit

        To the extent the aggregate Fair Market Value of the Common Stock
        (determined as of the date of grant) with respect to which any options
        granted hereunder are intended to be designated as Incentive Stock
        Options under the Plan (or any other incentive stock option plan of the
        Company or any Subsidiary) which may be exercisable for the first time
        by the optionee in any calendar year exceeds $100,000, such options
        shall not be considered incentive stock options.

     c. Exercise

        Subject to the power of the Committee under Section 1.10(b) above and
        except in the manner described below upon the death of the optionee, an
        Incentive Stock Option may be exercised only in installments as follows:
        up to one-half of the subject shares on and after the first anniversary
        of the date of grant, up to all of the subject shares on and after the
        second such anniversary of the date of the grant of such Option but in
        no event later than the expiration of the term of the Option.

        An Incentive Stock Option shall be exercisable during the optionee's
        lifetime only by the optionee and shall not be exercisable by the
        optionee unless, at all times since the date of grant and at the time
        of exercise, such optionee is an employee of the Company, any parent
        corporation of the Company or any Subsidiary, except that, upon
        termination of all employment (other than by death or by Total
        Disability followed by death in the circumstances provided below) with
        the Company, any parent corporation of the Company and any Subsidiary
        or Affiliate, the optionee may exercise an Incentive Stock Option at
        any time within three months thereafter but only to the extent such
        Option is exercisable on the date of such termination.

        In the event of the death of an optionee (i) while an employee of the
        Company, any parent corporation of the Company or any Subsidiary or
        Affiliate, or (ii) within three months after termination of all
        employment with the Company, any parent corporation of the Company and
        any Subsidiary or Affiliate (other than for Total Disability) or (iii)
        within three months after termination on account of Total Disability of
        all employment with the Company, any parent corporation of the Company
        and any Subsidiary, such optionee's estate or any person who acquires
        the right to exercise such option by bequest or inheritance or by
        reason  of the death of the optionee may exercise such optionee's
        Option at any  time within the period of one year from the date of
        death. In the case of clauses (i) and (iii) above, such Option shall be
        exercisable in full for all the remaining shares covered thereby, but
        in the case of clause (ii) such Option shall be exercisable only to the
        extent it was exercisable on the date of such termination.

        Notwithstanding the foregoing provisions regarding the exercise of an
        Option in the event of death, Total Disability or other termination of
        employment, in no event shall an Option be exercisable in whole or in
        part after the termination date provided in the Option.

     d. Transferability

        An Incentive Stock Option granted under the Plan shall not be
        transferable otherwise than by will or by the laws of descent and
        distribution.

2.4 NON-QUALIFIED STOCK OPTION GRANTS

     Each Non-Qualified Stock Option will be subject to the following
provisions:

     a. Term of Option

        A Non-Qualified Stock Option will be for a term of not more than ten
        years from the date of grant.

     b. Exercise

        The exercise of a Non-Qualified Stock Option shall be subject to the
        same terms and conditions as provided under Section 2.3(c) above.

     c. Transferability

        A Non-Qualified Stock Option granted under the Plan shall not be
        transferable otherwise than by will or by the laws of descent and
        distribution, except as may be permitted by the Board or the Committee.

2.5 AGREEMENTS

     In consideration of any Options granted to a Participant under the Plan,
each such Participant shall enter into an Option Agreement with the Company
providing, consistent with the Plan, such terms as the Committee may deem
advisable.