Unicel C-8410 Replacement Filter Cartridge for 100 Square Foot Jandy CS100 Diameter: 8 15/16-inch; length: 23 5/16-inch Top end cap: open, 4 0/0-inch inner diameter; bottom end cap: open, 4 0/0-inch inner diameter Pleat count: 143; filter media: 4-ounce reemay 2040; filter area: 100 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications