Aqua Kleen AK-6042 Unicel Replacement Filter Cartridge for Swimming Pool and Spa 65 sq. ft., 7 1/2" OD, Castle Top, Open Hole: 2 5/8" Bottom, 14 3/4" Long, AK-6042 Exact Fit for Unicel: C-7466 Exact Fit for Pleatco: PSD65-2 Exact Fit for Filbur: FC-2740 Guaranteed Perfect Fit - Extremely Durable - Wash & Reuse - Most Energy Efficient - Withstands High Pressures & Temperatures