Aqua Kleen AK-60036 Unicel Replacement Filter Cartridge for Swimming Pool and Spa 75 sq. ft., 7 1/2" OD, 2-5/8" w/bevel Top, Castle Bottom, 17 3/4" Long, AK-60036 Exact Fit for Unicel: C-7370 Exact Fit for Pleatco: PSD75 Exact Fit for Filbur: FC-2760 Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures