1

                                                                       EXHIBIT 4

                           SUN HYDRAULICS CORPORATION
                          EMPLOYEE STOCK PURCHASE PLAN
                       (AS AMENDED THROUGH JUNE 18, 2001)

1.       PURPOSES

         The Sun Hydraulics Corporation Employee Stock Purchase Plan (the
         "Plan") is intended to provide employees of Sun Hydraulics Corporation,
         a Florida corporation (the "Company") and its Subsidiaries with an
         opportunity to acquire shares of the Company's Common Stock at an
         advantageous price, with savings accumulated through payroll
         deductions. It is the intention of the Company that the Plan be an
         "employee stock purchase plan" under Section 423 of the Code. The
         provisions of the Plan shall, accordingly, be construed in a manner
         consistent with the requirements of that section of the Code.

2.       DEFINITIONS

         A.       "Agent" means the firm appointed by the Company's Board of
                  Directors to carry out the functions assigned to the Agent.

         B.       "Board of Directors" means the Company's Board of Directors.

         C.       "Closing Market Price" means the last sale price of the Common
                  Stock as reported on the Nasdaq National Market (or any other
                  exchange or quotation system, if applicable) on the date
                  specified; or if no sales occurred on such day, at the last
                  sale price reported for the Common Stock; but if there should
                  be any material alteration in the present system of reporting
                  sales prices of such Common Stock, or if such Common Stock
                  should no longer be listed on the Nasdaq National Market (or
                  other exchange or quotation system), or if the last sale price
                  reported shall be on a date more than 30 days from the date in
                  question, the market value of the Common Stock as of a
                  particular date shall be determined in such a method as shall
                  be specified by the Plan's Agent.

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

         E.       "Common Stock" means the Company's common stock, par value
                  $.001 per share, as traded on the Nasdaq National Market.

         F.       "Compensation" means cash compensation before any payroll
                  deductions for taxes or any other purpose, paid by the Company
                  or a Subsidiary to a Participant in respect of the service of
                  such Participant to the Company or a Subsidiary during an
                  Offering Period. This amount shall be deemed to include any
                  amount that the Participant has elected to defer for federal
                  income tax purposes under any 401(k) savings plan, cafeteria
                  plan or deferred compensation plan maintained by the Company
                  or a Subsidiary. Compensation shall not include any amount
                  paid to the Participant that

   2

                  (i) is paid during the relevant Offering Period under any
                  employee pension benefit plan (as defined in Section 3(2) of
                  the Employee Retirement Income Security Act of 1974, as
                  amended ("ERISA"); (ii) is calculated as an excess, incentive
                  compensation or bonus amount; and (iii) except as otherwise
                  provided in the preceding sentence, is not included in the
                  income of the Participant for federal income tax purposes.

         G.       "Enrollment Date" means August 1, 2001, and the first day of
                  any calendar quarter thereafter.

         H.       "Offering Date" means August 1, 2001, and the first day of any
                  calendar quarter thereafter.

         I.       "Offering Period" means the period from August 1, 2001 through
                  September 30, 2001, and thereafter, the three-month period
                  commencing on any Offering Date after the first Offering Date
                  and ending on the Purchase Date.

         J.       "Option" means the right of a Participant to acquire Common
                  Stock pursuant to Plan provisions.

         K.       "Participant" means an eligible employee who has authorized
                  payroll deductions for the purchase of Common Stock under the
                  Plan and has an account maintained by the Agent, containing
                  shares of Common Stock and/or Proceeds.

         L.       "Proceeds" means the total amount of cash accumulated for the
                  benefit of a Participant during a single Offering Period,
                  comprised of the aggregate of the payroll deductions taken
                  from the Participant's Compensation during such Offering
                  Period together with earnings thereon and dividends paid on
                  shares of Common Stock beneficially owned by the Participant.

         M.       "Purchase Date" means the last Trading Day of each Offering
                  Period.

         N.       "Subsidiary" means a corporation that is a subsidiary of the
                  Company within the meaning thereof as stated in Code Section
                  424(f). Each Subsidiary shall participate in the Plan unless
                  designated by the Board of Directors not to participate.

         O.       "Trading Day" means any day that the principal stock exchange
                  or other national market upon which the Common Stock is traded
                  is open for business.

                  Wherever appropriate in this Plan the singular shall include
         the plural; the masculine, the feminine; and vice versa.

3.       ELIGIBILITY

         All employees of the Company who have been employed for at least six
         (6) months as of the Enrollment Date shall be eligible to participate
         in the Plan, provided that no employee shall be eligible if such
         employee:


                                       2
   3

         A.       owns immediately after any Option is granted, stock possessing
                  five percent (5%) or more of the total combined voting power
                  or value of all classes of Company stock, applying the rules
                  of Code Section 424(d) in determining stock ownership, or

         B.       is an employee whose customary employment is twenty hours or
                  less per week, or whose customary employment is for not more
                  than five months in any calendar year.

         In addition, all employees of each Subsidiary shall be eligible to
         participate in the Plan to the extent they satisfy the requirements set
         forth in the preceding paragraph.

4.       EMPLOYEE PARTICIPATION AND PAYROLL DEDUCTIONS

         A.       An eligible employee shall become a Participant in the Plan by
                  completing and filing with the Company at least 20 days prior
                  to the Enrollment Date an authorization for a payroll
                  deduction on the form provided by the Company, together with
                  instructions to use the deductions to purchase shares of
                  Common Stock under the Plan. The Participant shall choose a
                  deduction in a whole percentage from 1% to 15%. As of each pay
                  day during each Offering Period, the Company will deduct the
                  specified amount from the Compensation payable to each
                  Participant. The Company will hold each Participant's Proceeds
                  in non-interest bearing accounts until each Participant's
                  proceeds are used to purchase shares. The Agent will perform
                  the record keeping function under the Plan, assuring that the
                  Agent, from the information provided to it by the Company,
                  will account for each Participant's deductions and maintain
                  each Participant's account. A Participant may not make any
                  separate cash payment into such account.

         B.       On each Offering Date, each Participant shall be granted the
                  right to purchase on the next Purchase Date such number of
                  shares of Common Stock as may be purchased by the
                  Participant's Proceeds accumulated during the preceding
                  Offering Period. No Participant, however, may be granted the
                  right to purchase shares of Common Stock under all Section 423
                  plans of the Company where the accrual is at a rate that
                  exceeds $25,000 of the Common Stock's fair market value,
                  determined at the time the option is granted, for any one
                  calendar year in which an option is outstanding for any part
                  of the year.

         C.       A Participant may not increase or reduce the amount of
                  Participant's payroll deductions until the next Enrollment
                  Date, except Participant may reduce the amount of
                  Participant's payroll deductions to 0% as described in Section
                  7. A Participant shall be deemed to have elected to purchase
                  all shares able to be purchased with the Proceeds on the
                  applicable Purchase Date.

5.       OPTION PRICE

         The price to Participants for each share to be purchased on a Purchase
         Date shall be the lesser of:


                                       3
   4

         A.       eighty-five percent (85%) of the Closing Market Price on the
                  Offering Date, or

         B.       eighty-five percent (85%) of the Closing Market Price on the
                  Purchase Date.

6.       METHOD OF PURCHASE

         A.       On each Purchase Date the Agent shall cause all Participants'
                  Proceeds, together with applicable Company contributions
                  during the preceding Offering Period, if any, to be applied to
                  the purchase of Common Stock from the Company.

         B.       As of the Purchase Date, the account of each Participant shall
                  be credited with a number of shares of Common Stock that were
                  able to be purchased with that Participant's Proceeds.

7.       WITHDRAWALS

         Prior to any Purchase Date, a Participant may give written notice to
         the Company or its agent of an intent to reduce the amount of payroll
         deductions to 0% and to withdraw the entire cash balance and earnings
         accumulated during the Offering Period preceding the said Purchase
         Date. The written notice shall effectuate a withdrawal only if the
         Agent has not purchased shares for the account of the notifying
         Participant. Such withdrawal will terminate the Participant's right to
         exercise any Options for that Offering Period. A Participant who
         withdraws shall not participate again in the Plan unless and until a
         new Enrollment Form is filed at least 20 days prior to the next
         Enrollment Date.

8.       TERMINATION OF EMPLOYMENT

         As soon as administratively practicable after the termination of a
         Participant's employment with the Company for any reason other than
         death, the Participant's Proceeds accumulated during the Offering
         Period in which his employment terminated will be refunded, and any
         shares of Common Stock held by the Agent will be distributed in kind.
         As an alternative to the latter, the terminated Participant may request
         that the Agent, at the Participant's expense, sell the Common Stock in
         the account and forward the net proceeds to the Participant.

9.       RIGHTS AS A SHAREHOLDER; DIVIDENDS; HOLDING AND ISSUANCE OF SHARES

         A.       A Participant shall have no rights as a shareholder with
                  respect to any shares of Common Stock offered hereunder until
                  completion of payment therefor. Shares purchased pursuant to
                  the Plan initially will be registered in the name of the Agent
                  as custodian for the account of the Participant entitled
                  thereto. In regard to shares paid for and in a Participant's
                  account, the Participant shall have all rights accruing to an
                  owner of record of such shares, including voting rights and
                  the right to receive dividends.


                                       4
   5

         B.       The Agent shall receive the dividends payable on the shares in
                  its custody and shall credit to the Proceeds account of each
                  Participant as beneficial owner of a certain number of shares
                  the amount of dividends attributable thereto. In the event
                  that the Participant has not authorized payroll deductions
                  during the Offering Period in which the Agent receives the
                  Participant's dividends, unless requested otherwise by the
                  Participant on notice from the Agent, the Agent shall
                  re-establish a Proceeds account to contain these dividends and
                  earnings thereon. In the event that the Participant's shares
                  have been distributed when dividends are received, the Agent
                  shall return said dividends to the Common Stock's transfer
                  agent for reissuance to the distributee of the shares.

         C.       Until such time as the Plan has been approved by the Company's
                  shareholders, the stock certificates representing all of the
                  shares purchased on behalf of Participants under this Plan
                  shall be retained by the Agent, and Participants may not
                  withdraw or sell such shares.

         D.       After the Plan has been approved by the Company's
                  shareholders, the stock certificate or certificates
                  representing the shares purchased on behalf of a Participant
                  on each Purchase Date shall be retained by the Agent until
                  such time as the Participant may request the Agent in writing
                  to distribute such shares to the Participant. The Company and
                  the Agent may establish such rules and procedures as they, in
                  their discretion, determine to be necessary or desirable with
                  respect to distributions of shares purchased under this Plan,
                  including any rules imposing limits on such distributions or
                  restricting the timing or frequency of such distributions they
                  may determine to be suitable.

10.      NONTRANSFERABILITY

         Neither payroll deductions credited to the account of a Participant nor
         any Options to purchase shares of common Stock under the Plan may be
         assigned, transferred, or alienated, and Options must be exercised only
         by the Participant during his lifetime.

11.      BENEFICIARY DESIGNATION AND RIGHTS

         A Participant may file with the Company's Chief Financial Officer, or
         such delegee appointed by the Chief Financial Officer, a written
         designation of beneficiary, or a revision thereof. In the absence of
         such designation, or if the named beneficiary predeceased the
         Participant, the Participant's estate shall be deemed to be the
         beneficiary. In the event of the Participant's death, the Agent shall
         apply the Proceeds to the purchase of shares on the next Purchase Date,
         and deliver all the Common Stock held for the deceased Participant to
         the beneficiary, together with any remaining Proceeds, subject to the
         Agent's receipt of Participant's death certificate and satisfactory
         evidence of the beneficiary's identity and acceptance of the Common
         Stock and Proceeds. The beneficiary shall have no rights under the Plan
         during the Participant's lifetime.


                                       5
   6

12.      SHARES AUTHORIZED; CHANGE IN CORPORATE STRUCTURE AND CAPITALIZATION

         A.       Subject to adjustment upon changes in the capitalization of
                  the Company, the maximum number of shares of Common Stock
                  which shall be made available for purchase under the Plan is
                  325,000 shares. The shares of Common Stock purchased under the
                  Plan may, at the election of the Company, be authorized but
                  unissued shares of the Company's Common Stock, authorized but
                  unissued treasury shares held by the Company, or shares of
                  Common Stock purchased on the open market by the Agent.

         B.       In the event of any change in the number of outstanding shares
                  of Common Stock by reason of a recapitalization, merger,
                  consolidation, reorganization, separation, liquidation, stock
                  split, stock dividend, combination of shares, or any other
                  change in the corporate structure or shares of stock of the
                  Company, the Board of Directors will make an appropriate
                  adjustment, in accordance with applicable provisions of the
                  Code and law, in the number and kind of shares which may be
                  offered under the Plan, both in the aggregate and as to each
                  Participant, the number of shares then subject to offerings
                  theretofore made, and the price of shares offered under the
                  Plan.

         C.       If the Company shall not be the surviving corporation in any
                  merger or consolidation, or survives only as a subsidiary of
                  another entity, or if the Company is to be dissolved or
                  liquidated, and unless a surviving corporation assumes or
                  substitutes new options within the meaning of Section 424(a)
                  of the Code, for all Options then outstanding under the Plan,

                  i.       the Purchase Date for all Options then outstanding
                           shall be accelerated to a date fixed by the Board of
                           Directors prior to the effective date of such merger
                           or consolidation or such dissolution or liquidation
                           and shall be deemed to be exercised, and

                  ii.      upon such effective date any unexercised Options
                           shall expire.

13.      SECURITIES LAWS

         The Plan is intended to comply with Rule 16b-3 of the Securities Act of
         1934, and shall be interpreted therewith. The Company shall not be
         obligated to issue any Common Stock pursuant to the Plan at any time
         when the shares have not been registered under the Securities Act of
         1933, as amended, and such other state and federal laws, rules or
         regulations as the Company or the Board of Directors deems applicable
         and, in the opinion of legal counsel for the Company, there is no
         exemption from the registration requirements of such laws, rules or
         regulations available for the issuance and sale of such shares.
         Further, all Common Stock acquired pursuant to the Plan shall be
         subject to, and may be sold only in a manner consistent with the
         Company's Policy on Confidentiality-Insider Trading and other policies
         concerning compliance with securities laws and insider trading, as the
         same may be amended from time to time.


                                       6
   7

14.      ADMINISTRATION

         A.       The Plan shall be administered by the Board of Directors.
                  Notwithstanding the preceding sentence, the Board of Directors
                  may delegate its authority to a Compensation Committee of at
                  least two members of the Board of Directors. The members of
                  the Compensation Committee shall serve at the pleasure of the
                  Board of Directors. The interpretation and construction of any
                  provision of the Plan, and the adoption of rules for
                  administering the Plan, shall be made by the Board of
                  Directors (or, in its place, the Compensation Committee).
                  Determinations made by the Board of Directors (or the
                  Compensation Committee) with respect to any matter or
                  provision contained in the Plan shall be final, conclusive and
                  binding upon the Company and all Participants, their
                  beneficiaries and legal representatives. Any rule adopted by
                  the Board of Directors (or the Compensation Committee) shall
                  remain in full force and effect unless and until amended or
                  repealed by the Board of Directors (or the Compensation
                  Committee).

         B.       The Board of Directors (or the Compensation Committee) shall
                  have the right to appoint the Agent and any other entity or
                  person, including Company employees, and to delegate to them
                  certain functions or services to be performed in connection
                  with Plan administration, and to name successors.

         C.       The Participant or beneficiary, as the case may be, shall bear
                  all costs and expenses associated with requests for the
                  issuance of stock certificates, the sale of Common Stock, and
                  a Participant's withdrawal from the Plan.

         D.       The Agent will mail to each Participant's home address a
                  quarterly statement showing the number of shares of Common
                  Stock held beneficially for the Participant, the amount and
                  derivation of cash in the Participant's Proceeds account, and
                  any purchases of shares in the Offering Period that closed
                  during the calendar quarter reflected in the statement.

         E.       If at any time the number of shares as to which Options have
                  been granted shall exceed the number of shares authorized for
                  purchase under the Plan on a certain Purchase Date, the number
                  of shares which may be purchased by each Participant shall be
                  reduced proportionately. Payroll deductions not able to be
                  used shall remain in the Participant's Proceeds account.

15.      AMENDMENT AND TERMINATION

         The Board of Directors may at any time terminate or amend the Plan,
         provided that no amendment may be made without approval of the
         shareholders of the Company if such amendment would increase the number
         of shares which may be available under the Plan, except by operation of
         Section 12 of the Plan, or materially modify the requirements as to
         eligibility for participation in the Plan.


                                       7
   8

16.      NONGUARANTEE OF EMPLOYMENT

         Neither eligibility to participate in, actual participation in, nor any
         provision of the Plan shall be construed as giving any eligible
         employee or Participant any employment right with the Company or a
         Subsidiary.

17.      AGENT FOR SERVICE OF PROCESS

         Legal process may be served upon the Secretary of the Company or the
         Chief Financial Officer, Sun Hydraulics Corporation, 1500 West
         University Parkway, Sarasota, FL 34243.


                                       8