This 45k water softener two tank unit, model PWSR45K, is designed for residential and light industrial use applications. These units use components that are NSF 61 listed. The state-of-the-art computer programming increases efficiency and saves salt and water. The PWSR series control valve is manufactured from high-tech materials, the PWSR Series valve has been engineered and tested to perform in the most demanding environments. It has built a reputation of being one of the most reliable valve platforms in the industry. The exchange media is a high capacity cations polystyrene resin that combines high operating capacity with excellent chemical and physical stability for long dependable life. The resin tank features a non-corrosive fiberglass tank with a thermoplastic inner liner. The brine tank is a combination brine maker and salt storage vessel and is made of tough, corrosion free, high-density polyethylene. All surfaces contacted by water are made from 100 % polymer components so that corrosion from acidic water and brine are no longer a concern.