Unicel C-7480 Replacement Filter Cartridge for 80 Square Foot Purex CF-80 Diameter: 7-inch; length: 19 5/8-inch Top end cap: open, 2 15/16-inch inner diameter; bottom end cap: open, 2 15/16-inch inner diameter Pleat count: 172; filter media: 4-ounce reemay 2040; filter area: 80 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications