Cardiovascular Systems Inc. Watch

from 10-K 2 pages Description of the Registrant’s Securities Registered Pursuant to Section 12 of the Securities Exchange Act of 1934

from S-3ASR 40 pages Cardiovascular Systems, Inc. and , as Trustee Indenture Dated as of ,

from S-3 42 pages Cardiovascular Systems, Inc. and , as Trustee Indenture Dated as of ,

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D/A ~5 pages Power of Attorney

from SC 13D ~5 pages Power of Attorney

from S-3 38 pages Cardiovascular Systems, Inc. and , as Trustee Indenture Dated as of ,

from 8-K 4 pages Termination of Fourth Amended and Restated Stockholders Agreement

from 8-K 19 pages Cardiovascular Systems, Inc. Registration Rights Agreement

from 8-K 8 pages Warrant to Purchase [Number of Shares] Shares of Common Stock of Cardiovascular Systems, Inc

from 8-K 2 pages Common Stock Number Common Stock Shares Cardiovascular Systems, Inc. Incorporated Under the Laws of the State of Delaware See Reverse Side for Certain Definitions Cusip 141619 106 Countersigned and Registered: American Stock Transfer & Trust Company Transfer Agent and Registrar by Authorized Signature This Certifies That Is the Owner of Fully Paid and Non-Assessable Shares of the Common Stock, Par Value of $0.001 Per Share, of Cardiovascular Systems, Inc. Transferable on the Books of the Corporation by the Holder Hereof in Person or by Attorney Upon Surrender of This Certificate Properly Endorsed. This Certificate Is Not Valid Unless Countersigned by the Transfer Agent and Registrar. Witness the Facsimile Signatures of Its Duly Authorized Officers. Dated: James E. Flaherty David L. Martin Secretary Chief Executive Officer

from S-1/A 3 pages [Face of Certificate] Common Stock Number Rdyn Incorporated Under the Laws of the State of Delaware [Logo] Common Stock Shares Cusip 76028w 10 7 See Reverse for Certain Definitions This Certifies That Is the Record Holder of Fully Paid and Nonassessable Shares of Common Stock, Par Value of $0.001 Per Share, of Replidyne, Inc. Transferable on the Books of the Corporation by the Holder Hereof in Person or by Duly Authorized Attorney Upon Surrender of This Certificate Properly Endorsed. This Certificate Is Not Valid Unless Countersigned and Registered by the Transfer Agent and Registrar. Witness the Facsimile Signatures of Its Duly Authorized Officers. Dated: /Sig/ Secretary /Sig/ President Countersigned and Registered: American Stock Transfer & Trust Company Transfer Agent and Registrar by Authorized Signature [Reverse of Certificate] Replidyne, Inc