Unicel C-4332 Replacement Filter Cartridge for 32 Square Foot Martec, Sonfarrel, Advantage Mfg Diameter: 4 15/16-inch; length: 11 7/8-inch Top end cap: open, 2-1/8-inch inner diameter; bottom end cap: open, 2-1/8-inch inner diameter Pleat count: 154; filter media: 3-ounce reemay 2033; filter area: 32 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications