... pump, with four ways shutoff valve and manual valveCartridge: PP, CTO, UDF, RO membrane and T33 cartridgeCapacity: 50GPD ... stagefunction1st5 micron PP fiber filtration wipes off impurities, algae, silt, sediment2ndGAC ... lifespan of the ro membrane are longer 4th1 micron pp sediment filter cartridge5thRO membrane,remove the micro impurities,colloid ...