PACK of 4 Hayward CX900RE, Star Clear Plus C-900, ALL AMERICAN 8018 Replacement Cartridge, Unicel C-8409, Pleatco PA90, Filbur FC-1292, Aladdin 19002 Swimming Pool Filter Cartridge PLEASE DOUBLE CHECK ... DOES YOUR CARTRIDGE MATCH THESE MEASUREMENTS ??? LENGTH: 17 3/8 inches ... OUTER DIAMETER: 8 15/16 inches ... INNER DIAMETER: 4 inches // 4 oz 100 square feet ... 174 pleats Replacement Cartridge fits: Hayward CX900RE, STAR CLEAR PLUS C-900 All American 8018, Unicel C-8409, Pleatco PA90, Aladdin 19002, Filbur FC-1292 MADE IN THE USA!