Exhibit 4.2

325976F QX 105 Friday, December 3, 2004 4:55:05 PM 105

COMMON STOCK

CM-

INCORPORATED UNDER THE LAWS OF THE STATE OF DELAWARE

This Certifies that

COMMON STOCK

CUSIP 208264 10 1

SEE REVERSE FOR CERTAIN DEFINITIONS

is the record holder of

FULLY PAID AND NONASSESSABLE SHARES OF COMMON STOCK, $0.001 PAR VALUE, OF

CONOR MEDSYSTEMS, INC.

transferable on the books of the Corporation in person or by duly authorized attorney on surrender of this certificate properly endorsed. This certificate shall not be valid until countersigned and registered by the Transfer Agent and Registrar.

WITNESS the facsimile seal of the Corporation and the signatures of its duly authorized officers.

Dated:

CHIEF FINANCIAL OFFICER

CHAIRMAN AND CHIEF EXECUTIVE OFFICER

COUNTERSIGNED AND REGISTERED

MELLON INVESTOR SERVICES LLC

TRANSFER AGENT AND REGISTRAR BY

AUTHORIZED SIGNATURE

325976b qx 105 Friday, November 19, 2004 1:59:11 PM

CONOR MEDSYSTEMS, INC.

THE CORPORATION WILL FURNISH WITHOUT CHARGE TO EACH STOCKHOLDER WHO SO REQUESTS A STATEMENT OF THE POWERS, DESIGNATIONS, PREFERENCES AND RELATIVE, PARTICIPATING, OPTIONAL, OR OTHER SPECIAL RIGHTS OF EACH CLASS OF STOCK OR SERIES THEREOF OF THE CORPORATION, AND THE QUALIFICATIONS, LIMITATIONS OR RESTRICTIONS OF SUCH PREFERENCES AND/OR RIGHTS. SUCH REQUESTS MAY BE MADE TO THE CORPORATION OR THE TRANSFER AGENT.

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 of survivorship and not as tenants in common

under Uniform Gifts to Minors

Act

(State)

COM PROP-

as community property

UNIF TRF MIN ACT-

Custodian (until age)

(Cust)

under Uniform Transfers

(Minor)

to Minors Act

(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, INCLUDING ZIP CODE, OF ASSIGNEE)

Shares of the capital stock represented by the within Certificate, and do 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,

X

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 WHATSOEVER.

SIGNATURE GUARANTEED:

THE SIGNATURE(S) MUST 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 S.E.C. RULE 17Ad-15.

KEEP THIS CERTIFICATE IN A SAFE PLACE. IF IT IS LOST, STOLEN OR DESTROYED THE CORPORATION WILL REQUIRE A BOND OF INDEMNITY AS A CONDITION TO THE ISSUANCE OF A REPLACEMENT CERTIFICATE.