Unicel C-7471-4 Replacement Filter Cartridge (4 Pack) Diameter: 7-inch; length: 26 1/16-inch Top end cap: open, 3 0/0-inch inner diameter; bottom end cap: open, 3 0/0-inch inner diameter Pleat count: 168; filter media: 4-ounce reemay 2040; filter area: 105 square feet Get more efficient filtration and better water clarity with unicel filters Case pack of 4