SCHEDULE 13G/A 0001493152-23-004833 0001406484 XXXXXXXX LIVE 2 Common Stock, par value $0.01 per share 03/31/2025 0001123494 HARVARD BIOSCIENCE INC 416906105 84 OCTOBER HILL RD HOLLISTON MA 01746 Rule 13d-1(b) HARVEY PARTNERS, LLC DE 2187500.00 0.00 2187500.00 0.00 2187500.00 N 4.96 IA See Item 2 for additional information. HARVARD BIOSCIENCE INC 84 OCTOBER HILL RD, HOLLISTON , Massachusetts 01746 This report is being filed by Harvey Partners, LLC, a Delaware limited liability company (the "Reporting Person"). As of March 31, 2025, Harvey SMidCap Fund, LP, a Delaware limited partnership ("SMidCap Fund"), held 127,151 shares of Common Stock and Harvey QP, LP, a Delaware limited partnership ("QP, LP"), held 72,893 shares of Common Stock. The Reporting Person is the investment manager of SMidCap Fund and QP, LP, and as such, possesses the sole power to vote and the sole power to direct the disposition of all securities of the Company held by SMidCap Fund and QP, LP. As of March 31, 2025, the Reporting Person held 1,987,456 shares of Common Stock in managed accounts. James A. Schwartz and Jeffrey C. Moskowitz, the Managing Members of the Reporting Person, share voting and investment power with respect to all securities beneficially owned by the Reporting Person. Based on the information set forth in the Annual Report on Form 10-K of the Company filed with the Securities and Exchange Commission on March 14, 2025, there were 44,074,475 shares of the Company's Common Stock outstanding as of March 5, 2025. As a result of the foregoing, for purposes of Reg. Section 240.13d-3, the Reporting Person is deemed to beneficially own 2,187,500 shares of Common Stock, or 4.96% of the Common Stock deemed issued and outstanding as of March 31, 2025. 120 White Plains Road, Suite 430, Tarrytown, NY 10591 Harvey Partners, LLC, a Delaware limited liability company. N IA 2,187,500 4.96% 2,187,500 0 2,187,500 0 N Y Y Y Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under ?? 240.14a-11. HARVEY PARTNERS, LLC /s/ Jeffrey C. Moskowitz 05/15/2025