EXHIBIT 4.2


                                SECOND AMENDMENT
                                     TO THE
                             CNS, INC. 1989 EMPLOYEE STOCK
                                  PURCHASE PLAN


         This SECOND Amendment to the CNS, Inc. 1989 Employee Stock Purchase
Plan (the "Plan") is made and adopted by CNS, Inc., a Delaware corporation, and
shall be effective as of January 1, 2001.

         WHEREAS, CNS, Inc. adopted, effective as of July 1, 1989, an employee
stock purchase plan in accordance with Section 423 of the internal Revenue Code;
and

         WHEREAS, CNS, Inc. (hereinafter referred as the "Company") amended the
Plan as of July 1, 1999 to extend the term of the Plan to July 1, 2009; and

         WHEREAS, as of December 31, 2000, there remained 11,493 share of stock
unissued under said Plan; and

         WHEREAS, the Board of Directors desires, subject to shareholder
approval, to increase the number of shares authorized under the Plan by an
additional 200,000 shares.


                                    AMENDMENT

1.       THE FIRST SENTENCE OF SECTION 4, SUBSECTION (b) SHALL BE AMENDED IN ITS
ENTIRETY TO READ AS FOLLOWS:

         (b)      The Plan shall be carried out in one or more Phases, each
                  Phase being for a period of six months, or such shorter or
                  longer period of time (not to exceed 27 months) as may be
                  determined by the Committee prior to the commencement of a
                  Phase.

2.       SECTION 6 IS AMENDED BY ADDING A NEW PARAGRAPH TO READ IN FULL AS
FOLLOWS:

         Once enrolled in the Plan, a Participant will continue to participate
         in the Plan until he or she ceases to be an Eligible Employee,
         withdraws from the Plan pursuant to Section 9 or reaches the end of the
         Plan Phase. A Participant who withdraws from the Plan pursuant to
         Section 9 may again become a Participant, if he or she is then an
         Eligible Employee, on the Commencement Date of any subsequent Phase by
         proceeding as provided in Section 7. A Participant whose payroll
         deductions were discontinued because of Section 8(a)(iv)(A) will
         automatically resume participation at the beginning of the earliest
         Phase of the Plan ending in the next calendar year, if he or she is
         then an Eligible Employee.


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3.       SECTION 8, SUBSECTION (a)(iv)(a) SHALL BE AMENDED IN ITS ENTIRETY TO
READ AS FOLLOWS:

         A.       Which permits his rights to purchase stock under all employee
                  stock purchase plans of the Company, its Subsidiaries or its
                  parent, if any, to accrue at a rate which exceeds the lesser
                  of Twenty-Five Thousand Dollars ($25,000) of the Fair Market
                  Value of such stock (determined at the time such option is
                  granted) for each calendar year in which such option is
                  outstanding at any time or 10,000 shares per Phase under the
                  Plan; or

4.       SECTION 8, SUBSECTION (b)(i) SHALL BE AMENDED IN ITS ENTIRETY TO READ
AS FOLLOWS:

         (i)      Unless a Participant gives written notice to the Company
                  pursuant to Section 9 prior to the Termination Date of a
                  Phase, his option for the purchase of shares will be exercised
                  automatically for him as of Termination Date for the purchase
                  of the number of full shares of Company common stock which the
                  accumulated payroll deductions in his account at that time
                  will purchase at the applicable option price, but in no event
                  shall the number of full shares be greater than the number of
                  full shares to which a Participant would have been eligible to
                  purchase under Section 8(a)(i), and subject to the limitations
                  set forth in Section 10 hereof.

5.       SECTION 8, SUBSECTION (b)(iii) SHALL BE AMENDED IN ITS ENTIRETY TO READ
AS FOLLOWS:

         (iii)    The Committee may appoint a registered broker dealer to act as
                  agent for the Company in holding and performing ministerial
                  duties in connection with the Plan, including, but not limited
                  to, maintaining records of stock ownership by Participants and
                  holding stock in its own name for the benefit of the
                  Participants. No trust or escrow arrangement shall be express
                  or implied by the exercise of such duties by the agent. A
                  Participant may, at any time, request of the agent that any
                  shares allocated to the Participant be registered in the name
                  of the Participant or in joint tenancy with the Participant,
                  in which event the agent shall issue a certificate for the
                  whole number of shares in the name of the Participant (and his
                  joint tenant, if any) and shall deliver to the Participant any
                  cash for fractional shares, based on the then Fair Market
                  Value of the shares on the date of issuance.

6.       SECTION 8 IS AMENDED BY ADDING A NEW SUBPARAGRAPH (c) TO READ AS
FOLLOWS:

         (c)      Dividend Reinvestment.

                           Unless the Committee designates otherwise, and except
                           as provided in this section, dividends on a
                           Participant's shares will automatically be reinvested
                           in additional shares of stock of the Company. If a
                           Participant


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                           desires to receive dividends in the form of cash, he
                           must request that a certificate for such shares be
                           issued in the name of the Participant by filing an
                           appropriate form with the Company. Any shares
                           purchased through the reinvestment of dividends may
                           be issued from the shares authorized under this Plan
                           or purchased on the open market, as directed by the
                           Committee. If the shares are purchased directly from
                           the Company, the purchase price shall be the Fair
                           Market Value of a share or the date such dividends
                           are paid. Otherwise, the purchase price may be an
                           average of shares purchased on the open market with
                           the aggregate amount of dividends.

7.       SECTION 9 IS AMENDED BY ADDING A NEW SUBPARAGRAPH (c) TO READ AS
FOLLOWS:

         (c)      Notwithstanding the provisions of Section 9(a) above, if a
                  Participant files reports pursuant to Section 16 of the
                  Securities Exchange Act of 1934 (at the Commencement Date of a
                  Phase or becomes obligated to file such reports during a
                  Phase) then such a Participant's participation, including the
                  ability to make changes and withdrawals, in a Phase and in the
                  Plan shall be in accordance with Section 10b5-1 promulgated
                  under the Securities Exchange Act of 1934.

8.       SECTION 10, SUBSECTION (a) SHALL BE AMENDED IN ITS ENTIRETY TO READ AS
FOLLOWS:

         (a)      The maximum number of shares of the Company's common stock to
                  be issued upon the exercise of options to be granted under the
                  Plan after December 31, 2000 shall be 211,493 representing
                  11,493 shares that remained unissued as of December 31, 2000
                  and an additional 200,000 shares which are subject to approval
                  by the shareholders with 12 months of Board authorization for
                  such shares. Such shares may, at the election of the Board of
                  Directors, be either shares authorized but not issued or
                  shares acquired in the open market by the Company. Shares
                  subject to the unexercised portion of any lapsed or expired
                  option may again be subject to option under the Plan.

9.       SECTION 19, SUBSECTION (c) SHALL BE AMENDED IN ITS ENTIRETY TO READ AS
FOLLOWS:

         (c)      "Pay" is the regular pay for employment for each employee as
                  annualized for a twelve (12) month period, including salary
                  reduction contributions by the Participant under any plan of
                  the Employer pursuant to Code ss.ss. 401(k) or 125, but
                  exclusive of overtime, commissions, bonuses, disability
                  payments, shift differentials, incentives and other similar
                  payments, determined as of the Commencement Date of each
                  Phase.

10.      SECTION 19 IS AMENDED BY ADDING A NEW SUBPARAGRAPH (d) TO READ AS
FOLLOWS:

         (d)      "Fair Market Value" of a share of stock of the Company shall
                  be the closing price of the stock on the applicable date or
                  the nearest prior business day on which trading occurred on
                  the exchange on which the stock is traded or on the Nasdaq
                  Stock Market. If the common stock is not traded on any
                  exchange or listed on the


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                  Nasdaq Stock Market, the Fair Market Value of a share of
                  common stock of the Company shall be determined by the
                  Committee for each valuation date in a manner acceptable under
                  Section 423 of the Internal Revenue Code of 1986, as amended.

11.      THE PLAN SHALL BE OTHERWISE AMENDED FOR NON-SUBSTANTIVE AND CONFORMING
CHANGES AS IS DETERMINED TO BE NECESSARY BY MANAGEMENT OF THE COMPANY.

12.      EXCEPT AS OTHERWISE AMENDED ABOVE, THE PLAN SHALL REMAIN IN FULL FORCE
AND EFFECT.

         IN WITNESS WHEREOF, CNS, Inc. has caused this Second Amendment to the
Plan to be executed on the date written below by its proper officer, who has
been duly authorized by its Board of Directors, has caused this Second Amendment
to be executed on the date written below.

                                                     CNS, INC.

Dated: January 18, 2001                     By   /s/ Daniel Cohen
                                                 -------------------------------
                                            Its  Chief Executive Officer
                                                 -------------------------------