Unicel 5CH-35 Replacement Filter Cartridge for 35 Square Foot Elite Spas By Maax Diameter: 5 5/8-inch; length: 8-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: 203; filter media: 3-ounce reemay 2033; filter area: 35 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications