The H2O-GAC/KDF Plus RO Filter Cartridge uses the coconut carbon block that removes the most important impurities from water. It removes the smell and taste of chlorine from drinking water. The H2O-GAC/KDF Plus Filter Cartridge uses pollution free activated carbon. It filters heavy metals, dirt, hydrogen sulfur, cyst, organics, rust, and sediments. It was to be used with the H2O-RCT-CP countertop RO system. It basically removes most of the EPA listed contaminants. The flow rate is 0.5 gpm. The length of the filter cartridge is 10?, filter diameter is 2.5?, and the length of the housing is 10?.