Unicel C-7678 Replacement Filter Cartridge for 50 Gpm Pac-fab Diameter: 7 7/8-inch; length: 11 1/8-inch Top end cap: open, 3-1/16-inch inner diameter; bottom end cap: open, 3-1/16-inch inner diameter Pleat count: 152; filter media: 4-ounce reemay 2040; filter area: 50 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications