Unicel C-9603 Replacement Filter Cartridge for 150 Square Foot Aquatemp, Cooper CF 150 Performax Diameter: 9-inch; length: 22 5/8-inch Top end cap: open with step, 3 15/16-inch inner diameter; bottom end cap: open with step, 3 15/16-inch inner diameter Pleat count: 226; filter media: 4-ounce reemay 2040; filter area: 150 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications