Woder WD-HM-REP Cartridge.  For higher than EPA's recommended level of Heavy Metals / Lead. The WD-HM-REP is the first stage replacement cartridge for the following dual stage systems: Woder WD-D-HM-ADV-DC Water Filtration System. Woder WD-D-HM-ADV-JG Water Filtration System. Cartridge lifespan: 1 year under warranty. Selective Filtration™ Our proprietary Selective Filtration™ technology removes 99.9% of contaminants while leaving in all essential minerals. Reverse Osmosis (RO) filters also remove 99.9% of contaminants, however, RO also remove ALL the minerals found in tap water – including minerals your body needs. RO systems can waste thousands of gallons of water annually while flushing out contaminants down the drain.