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                                                                     EXHIBIT 4.3

[Front]


              Incorporated under the laws of the State of Delaware

                                    NETSCOUT

NUMBER                                                 SHARES
NET

                                                       Common Stock See
                                                       Reverse for
                                                       Certain Definitions


                             NetScout Systems, Inc.




                   FULLY PAID AND NONASSESSABLE SHARES OF THE
                 PAR VALUE OF $.001 EACH OF THE COMMON STOCK OF

NetScout Systems, Inc. transferable upon the books of the Corporation in person
or by attorney upon surrender of this certificate duly endorsed or assigned.
This certificate and the shares represented hereby are subject to the laws of
the State of Delaware and to the Certificate of Incorporation and By-Laws of the
Corporation as from time to time amended.

       This certificate is not valid unless countersigned by the Transfer Agent
and registered by the Registrar.

       IN WITNESS WHEREOF, NetScout Systems, Inc. has caused its facsimile
corporate seal and the facsimile signatures of its duly authorized officers to
be hereunto affixed.

Dated:


         Anil Singhal                           Anil Singhal
         Treasurer                              President


Countersigned and Registered: Mellon Investor Services, LLC
                              Transfer Agent and Registrar


                               By Authorized Signatory

[Reverse Side]

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       THE CORPORATION IS AUTHORIZED TO ISSUE MORE THAN ONE CLASS OR SERIES OF
STOCK. A COPY OF THE PREFERENCES, POWERS, QUALIFICATIONS AND RIGHTS OF EACH
CLASS AND SERIES WILL BE FURNISHED BY THE CORPORATION UPON WRITTEN REQUEST AND
WITHOUT CHARGE.

       The following abbreviations, when used in the inscription on the face of
this certificate, shall be construed as though they were written out in full
according to applicable laws or regulations:

TEN COM - as tenants in common           UNIF GIFT MIN ACT-____Custodian_____
TEN ENT - as tenants by the entireties                    (Cust)       (Minor)
JT TEN  - as joint tenants with right           under Uniform Gift to Minors
          of survivorship and not as            Act__________
          tenants in common                         (State)

       Additional abbreviations may also be used though not in the above list.

For value received, __________________ hereby sell, assign, and transfer unto
[PLEASE INSERT] SOCIAL SECURITY OR OTHER IDENTIFYING NUMBER OF ASSIGNEE
________________________________________________________________________________

[PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS OF ASSIGNEE]

________________________________________________________________________________
________________________________________________________________________________
________________________________________________________________________________

Shares of the capital stock represented by the within Certificate, and does
hereby irrevocably constitute and appoint ______________________________________
Attorney to transfer the said stock on the books of the within-named Corporation
with full power of substitution in the premises. Dated,_______________


             ---------------------------------------------------------------
             NOTICE: The signature to this assignment must correspond with
             the name as written upon the face of the certificate, in every
             particular, without alteration or enlargement or any change
             whatever.

SIGNATURE(S) GUARANTEED:

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The signature(s) should be guaranteed by an eligible
guarantor institution (banks, stockbrokers, savings
and loan associations and credit unions with
membership in an approved signature guarantee
medallion program), pursuant to SEC Rule 17Ad-15.