QTY OF 4: 1,000 Gallon Cartridge Filter Pump, For Swimming Pools Up To 15', Cartridge Filter Pump Provides Excellent Water Filtration & Is Easy To Use, Just Hook Up Hoses & Plug In, Results Will Be Faster Water Circulation, Improved Filtration & A Superior Swim Experience, Comes Complete With 1 "A" Cartridge & Uses Readily Available "A" Cartridge TV #440-534, Replace Used Cartridges After 2 Weeks Use, 1,000 Gallon Per Hour Flow Rate.