Unicel C-6310 Replacement Filter Cartridge for 100 Square Foot Waterway Dyna-flo XL Diameter: 6 9/16-inch; length: 17 13/16-inch Top end cap: open, 2-3/8-inch inner diameter; bottom end cap: open, 2-3/8-inch inner diameter Pleat count: 221; 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