Unicel C-7403 Replacement Filter Cartridge for 60 Square Foot Doughboy Skim-line Diameter: 7-inch; length: 17 5/8-inch Top end cap: injection molded knob handle, 0-inch inner diameter; bottom end cap: open, 1-1/2-inch inner diameter Pleat count: 144; filter media: 4-ounce reemay 2040; filter area: 60 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications