summer waves p57100202 swimming pool pump filter cartridge, type a/c pack of 2 summer waves 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.