X0306 4/A 2012-12-20 2012-12-21 0 0001024795 SUN HYDRAULICS CORP SNHY 0001234878 KOSKI CHRISTINE L 1 0 1 0 0001234877 KOSKI BEVERLY 0 0 1 0 0001234879 KOSKI FAMILY LP 0 0 1 0 0001234880 KOSKI ROBERT C 0 0 1 0 0001234881 KOSKI THOMAS L 0 0 1 0 Common Stock 2012-12-20 4 S 0 5699 26.2918 D 100000 D Common Stock 2012-12-20 4 S 0 13701 26.2918 A 3331755 D The reporting person is amending the transaction reported in the previously filed Form 4 of 12/20/12 to correct the amount of shares sold (which was incorrectly reported in the original Form 4 as 9,700 shares) and end of period holdings (which was incorrectly reported in the original Form 4 as 95,999 shares). The range of prices for the transactions reported is $26.101 - $26.58. The undersigned hereby undertakes to provide upon request by the Commission staff, the issuer, or a security holder of the issuer, full information regarding the number of shares sold at each separate price. Shares owned directly by Robert C. Koski. The reporting person is amending the transaction reported in the previously filed Form 4 of 12/20/12 to correct the amount of shares sold (which was incorrectly reported in the original Form 4 as 9,700 shares) and end of period holdings (which was incorrectly reported in the original Form 4 as 3,335,756 shares). Shares owned directly by Koski Family Limited Partnership. Shares owned indirectly by Beverly Koski, Christine L. Koski, Robert C. Koski and Thomas L. Koski, each of whom is a general partner of the partnership or the controlling person of a corporate general partner of the partnership. Gregory C. Yadley, as Attorney-in-Fact for CHRISTINE L. KOSKI, BEVERLY KOSKI, KOSKI FAMILY LIMITED PARTNERSHIP, ROBERT C. KOSKI AND THOMAS L. KOSKI 2012-12-27