Five stage reverse osmosis systems fit nicely under a kitchen sink providing great tasting water for the whole family. Filtration stages include a sediment filter for dirt, rust and other sediment contaminants. Two carbon block filters for chlorine taste and odor reduction. One 50 GPD reverse osmosis membrane, which is the heart of the RO system, filters out particles as small as 1/10,000 of a micron and a final stage polishing filter for fresh tasting water every time. The RO systems come complete with installation hardware, and a 3 gallon water storage tank. Recommended inlet water pressure is 40 psi with maximum water hardness of 10 GPG.