The Summer Waves P57100202 Swimming Pool Pump Filter Cartridge fits RX & SFX 1000, RX & SFX 1500, RP & SFS 700/800, RP & SFS 1000, RP & SFS 1500, RP & SFS 2000 (2013 & newer), and CP2000-C model canisters. It features a basket for chlorine tablets and built-in chlorinator that keeps tablets suspended. Made with ultra-fine, heavy-duty filter paper. Filter cartridges come in a pack of 2.