Summer Escapes Universal Replacement Swimming Pool Filter Cartridges - A or C Type (4-Pack) - RP800, RP1000, RP2000, SFS1000, SFS2000 + More Cleans impurities out of your pool for a safer swimming experience Each cartridge measures 8 inches long and 4.13 inches in diameter Each filter features a built-in open cage in the middle to hold a 1 inch chlorine tablet of your choice (tablet not included) Fits filter pump models RP800, RP1000, RP2000, SFS1000, SFS2000 and all other models using filters with dimension 8 inches x 4.13 inches Package of four saves you time and money