Stanley PoolTec 12278 Replacement Filter Cartridge for Intex Recreation Sand N Sun Model 51 and 52, B 59905 Equivalent to: Pool master 12277, Pleatco PIN20, Unicel C-5315 Replacement for Intex Recreation Sand N Sun Model 51 & 52, Model B 59905 5.75" diameter x 10" high 3 oz. media 15 square feet