Unicel 4CH-22 Pool Filter Cartridge Diameter: 4 15/16-inch; length: 6 5/8-inch Top end cap: open, 2-1/8-inch inner diameter; bottom end cap: 1-1/2-inch male thread/mpt, 0-inch inner diameter Pleat count: 212; filter media: 3-ounce reemay 2033; filter area: 25 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications