The Hydronix UDF-10KDF.5 is a 2.5" x 10" KDF replacement with 0.5 lbs of KDF media. For use in many water filter systems, especially whole house filter systems. This advanced Hydronix water filter replacement cartridge primarily reduces the bad taste/odor of chlorine and other chemicals in water. It is a multi-purpose water filter cartridge that uses KDF media to reduce heavy metals such as aluminum, arsenic, mercury, cadmium, copper, iron, lead, and other water soluble heavy metals as well as particulates like sediment, dirt, rust, sand, silt, limescale, and more. The versatility and effectiveness of the UDF-10KDF.5 makes it a popular whole house filter.