All American Cartridges Hayward CX580XRE, Swim Clear C3025, Unicel C-7483, Pleatco PA81, Filbur FC-1225 Replacement Swimming Pool Filter Cartridges PACK of 4 PLEASE DOUBLE CHECK ... DOES YOUR CARTRIDGE MATCH THESE MEASUREMENTS ??? LENGTH: 19 5/8 inches ... OUTER DIAMETER: 7 inches ... INNER DIAMETER: 3 inches tolerance plus or minus 1/16"... 325 square feet ... 176 PLEATS Replacement Cartridge fits: Hayward CX580XRE, Swim Clear C3025, Pleatco PA81, Filbur FC-1225, Unicel C-7483 MADE IN THE USA! ... When you make a purchase, you're supporting a small business with the entrepreneurial spirit that made America great!