... PP(CTO)+RO+T33+UV(Stainless Steel Shell) Filter typePictureMain FunctionSuggest Using TimePP filter To remove sand,dirt, worn and rust ... particles6 monthsGAC-Granular Activated Carbon Filter To Adsorb the Chlorine ,VOC Organic Matter,Odor,Smell ... mineral substance and dissolved matter and chemical12 monthsT33-Post Carbon Filter To absorb the odor,and adjust the taste6 months ...