This three stage Kwik-Change zero waste reverse osmosis system combines the patented zero waste technology with the easy to replace Kwik-Change filters technology giving you simple and Kwik filter changes plus water savings on the water bill and for the environment. Stage 1 is a five micron carbon block filter that provides a reduction of chlorine, chloramines and other materials that cause bad taste and odors. It traps particulate matter like dirt, rust, sand silt and sediment that will affect the taste and appearance of the water. Stage 3 is the heart of the reverse osmosis system membrane. This semi permeable membrane is 1/10,000 of a micron and will effectively reduce total dissolved solids, sodium and a wide range of contaminants such as arsenic, lead, percolate, chromium, copper and radium. It will also remove over 99.95 percent cysts such as giardia and cryptosporidium. Stage 4 is a high quality GAC final filter.