undersink 5-stage RO water purifierAutomatically-Flush RO water purifier with dust-proofDetails of filteringstage 1: 5 Micro PP Fibre Filter eliminates sand, rust, mud, sediment etc. stage 2: Granular Activated Carbon adsorbs chlorine and organic matter in waterstage 3: Sintered Activated Carbon efficiently removes the bad color, taste and odor in water.stage 4: RO membrane removes almost compeletely all contaminants, solute and ions in water.stage 5: Postpositional activated carbon improves the taste of water.