Purenex SS-1 Countertop Water Filter, Chrome Replacement cartridge lasts 1 year for a family of four To make sure that the plastic wrap that is on the filter cartridge that is inside the filter housing, if there is one, is taken off before use To take off the hose clamp and put on the needed adapter that is included inside the unit box. Removes Lead, mercury, crypto, giardia, MTBE, VOC's, THM's Removes Chlorine and Chloramines Less than 0.09 a gallon NSF Tested and certified