Unicel 6CH-75 Replacement Filter Cartridge for 75 Square Foot Top Load Diameter: 6-inch; length: 19 3/4-inch Top end cap: semi-circular handle, 0-inch inner diameter; bottom end cap: 1-1/2-inch male thread/mpt, 0-inch inner diameter Pleat count: 158; filter media: 3-ounce reemay 2033; filter area: 75 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications