Unicel C-8417 Replacement Filter Cartridge for 175 Square Foot Hayward C1750RE, Hayward C1900RE, Waterway Pro Clean 175 Diameter: 8 15/16-inch; length: 28 3/16-inch Top end cap: open with molded gasket, 4 0/0-inch inner diameter; bottom end cap: open with molded gasket, 4 0/0-inch inner diameter Pleat count: 202; filter media: 4-ounce reemay 2040; filter area: 175 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications