Unicel C-4325 Replacement Filter Cartridge for 25 Square Foot Hayward CX225re, American Commander II, In-line Diameter: 4 5/8-inch; length: 11 7/8-inch Top end cap: open, 2-1/16-inch inner diameter; bottom end cap: open, 2-1/16-inch inner diameter Pleat count: 138; filter media: 3-ounce reemay 2033; filter area: 25 square feet Get more efficient filtration and better water clarity with Unicel filters Longer time between cleanings; meets oem specifications