purity water filter 1) six stage reverse osmosis water filtration system with AUTO ... , UDF, RO membrane and T33 cartridgeCapacity: 50GPD stagefunction1st5 micron PP fiber filtration wipes off impurities, algae, silt, sediment2ndGAC filtration ... make the lifespan of the ro membrane are longer 4th1 micron pp sediment filter cartridge5thRO membrane,remove the micro impurities,colloid,metal,bacterials ...