Unicel C-8310 Replacement Filter Cartridge for 100 Square Foot Rec. Warehouse, Jacuzzi Leisure Diameter: 8 1/2-inch; length: 15 3/16-inch Top end cap: open, 2-3/16-inch inner diameter; bottom end cap: open, 3-1/8-inch inner diameter Pleat count: 186; filter media: 3-ounce reemay 2033; filter area: 100 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications