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                                      MANAGEMENT SERVICES AGREEMENT

         This  Management  Services  Agreement  ("Agreement")  is entered into
effective the 27th day of July, 2001 by and between Sterling  International,
Inc.  ("Sterling")  and Centrex,  Inc. ("Company").

         WHEREAS, the Company desires to engage Sterling, an independent
contractor, and Sterling desires to provide specified Operations Management
services not in connection with fund raising activities and specifically
excluding the functions and activities of, accounting, legal, human resources
and finance to the Company on and subject to the terms and conditions set forth
herein; and

     NOW, THEREFORE, for good and valuable consideration, the receipt, adequacy
and sufficiency are acknowledged, the parties agree as follows:

1. Engagement.  The Company engages  Sterling and Sterling  accepts the
engagement from the Company to perform all aspects of  operations  for the
Company upon the terms and  conditions  of this Agreement.

2. Scope of Engagement. Sterling agrees to devote his good faith diligent
efforts for the Company to perform any and all operations functions for the
Company and such other duties and tasks as shall be assigned to Sterling from
time to time by the Company. Sterling shall make monthly reports outlining
activities in the following areas:

a.   Coordination of product development with the inventor and inventor's staff
b.   Market Research and the identification of potential markets.
c.   Manufacturing alliances.
d.   Distribution relationships and alliances.
e.   Pricing and Promotional activities
f.   Revenue and expense responsibility
g.   Customer service
h.   Product delivery
i.   Operations management and staffing
j.   Budgets and projections

3. Term of Engagement. This Agreement shall remain in effect for one year from
the effective date, unless terminated for cause by prior written notice. This
Agreement will continue for successive one-year terms with the exception of the
Stock Options, which are vested on the occurrence of milestone events.

4.       Compensation. Sterling shall be paid the following compensation:

        (a)  Stock Options. Options to purchase 15% of the outstanding
             shares of the Company (1,342,500) shares of common stock of
             the Company at par value ($0.001) are hereby granted and
             vesting occurs upon the achievement of the milestone events as
             follows:
             Execution of this Agreement                        250,000 options
             Marketing Plan accepted by the Board of Directors  250,000 options
             Production of product for commercial use           250,000 options
             Product sales in excess of $1,000,000              250,000 options
             First Quarter of profitable operations             342,500 options

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        (b)  Expense Reimbursement. Sterling shall be reimbursed all out of
             pocket business expenses incurred in accordance herewith. The
             Company shall approve a budget for expenses that may be
             modified from time to time as conditions warrant. All expense
             reimbursements approved by the Company shall be supported by
             appropriate receipts. The Company shall be entitled to deduct
             from any payments all federal, state and local income, FICA
             and other required tax withholdings.

        (c)  Management  Fee.  Sterling shall receive  $25,000 upon execution
             of this Agreement and a fee in the amount of $10,000 at the
             beginning of each month  commencing  August 1, 2001. In addition to
             the management  fee,  Sterling shall receive incentive compensation
             equal to 15% of year-to-date  net profit,  payable within 30 days
             of the end of each  quarter.  In the event  that the  Company is
             unable to fund the  payment of the  management fee or the incentive
             compensation,  Sterling agrees that the Company will record the
             liability for and pay Sterling as soon as funds are available to
             the Company.

        (d)  No Employee Benefit. Sterling agrees that Sterling shall have
             no participation in any employee benefit programs now in
             effect or hereafter established by the Company, and Sterling
             shall not be entitled to participate in health, accident, and
             life insurance programs, vacation benefits, and pension,
             profit sharing or other employee benefits.

     5.  Termination.  This  Agreement  may be  terminated  for  cause by prior
notice  given by either party.

     6.  Independent  Contractor.  Sterling is an  independent  contractor  and
not an  employee, partner,  joint  venturer  or other  representative  of the
Company.  Sterling is not under the direct or indirect  control of the  Company.
All  references  in the  Agreement  to  "Sterling" include the Sterling and
Sterling's directors, officers, employees and affiliates.

     7.  Miscellaneous.

        (a)       Notices. Any notice, request, demand or other communication
                  required to be made or which may be given to either party
                  hereto shall be delivered by certified U.S. mail, postage
                  prepaid, to that party's attention at the address set forth
                  below or at such other address as shall be changed from time
                  to time by giving notice hereunder.

                  Centrex, Inc.
                  8908 South Yale Avenue - Suite 409
                  Tulsa, Oklahoma 74137

                  Sterling International, Inc.
                  7010 Spinnaker Lane
                  Oklahoma City, Oklahoma 73116

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              (b) Entire Agreement. This document constitutes the complete and
                  entire employment agreement between the parties hereto with
                  reference to the subject matters hereof. No statement or
                  agreement, oral or written, made prior to or at the signing
                  hereof, and no prior course of dealing or practice by either
                  party shall vary or modify the written terms hereof.

              (c) Headings. The headings and captions contained in this
                  Agreement are for ease and convenience of reference only and
                  shall not be deemed for any purpose to affect the substantive
                  meaning of the rights and duties of the parties hereto in any
                  way.

              (d) Binding  Effect.  This Agreement shall be binding upon and
                  inure to the benefit of the parties hereto and there
                  respective successors and assigns.

              (e) Counterparts. This Agreement may be executed in multiple
                  counterparts, each of which has the same text and each of
                  which shall be deemed an original for all purposes, but
                  together they constitute one single and the same agreement.

              (f) Amendments. This Agreement may be amended only by a written
                  document signed by the parties and stating that the document
                  is intended to amend this Agreement.

              (g) Applicable  Law.  This  Agreement  shall  be  governed  by
                  and  construed  in accordance with Oklahoma law.

              (h) Resolution of Disputes. The parties agree to resolve all
                  disputes arising under or in connection with this Agreement by
                  final and binding arbitration, which either party may initiate
                  60 days after the parties have failed to reach a mutually
                  acceptable agreement after negotiating in good faith to do so.
                  The arbitration shall be conducted in accordance with the
                  Commercial Rules of Arbitration of the American Arbitration
                  Association, held in Tulsa, OK.

              (i) Additional  Documents.  The parties  hereto  shall enter into
                  and execute such additional  agreements,  understandings,
                  documents  or  instruments  as may be necessary to implement
                  the intent of this Agreement.

              (j) Cumulative Remedies. The remedies of the parties as set forth
                  herein are cumulative and may be exercised individually or
                  together with one or all other remedies, and are not exclusive
                  but instead are in addition to all other rights and remedies
                  available to the parties at law or in equity.

              (k) Severability. If any provision of this Agreement or the
                  application thereof to any person or circumstances shall be
                  held invalid or unenforceable to any extent, the remainder of
                  this Agreement and the application of such provisions to other
                  persons or circumstances shall not be affected thereby and
                  shall be enforced to the greatest extent permitted by law.

              (l) Waiver. The failure of a party to enforce any provision of
                  this Agreement shall not constitute a waiver of such party's
                  right to thereafter enforce such provision or to enforce any
                  other provision at any time.

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     IN WITNESS WHEREOF, the parties hereto have duly caused this Agreement to
be executed effective this 27th day of July 2001.


Sterling International, Inc.                   Centrex Inc.

        /s/ JOE MCEUEN                                  /s/ GIFFORD MABIE
BY:___________________________________         BY: ____________________________
   Joe McEuen, President                           Gifford Mabie, President



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