Unicel C-7605 Replacement Filter Cartridge for 50 Square Foot Baker-hydro HM-50 Diameter: 7-inch; length: 19 5/8-inch Top end cap: injection molded knob handle, 0-inch inner diameter; bottom end cap: injection molded cone adapter, 0-inch inner diameter Pleat count: 110; filter media: 4-ounce reemay 2040; filter area: 50 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications