The Schneider Electric (Barber Colman) VB-7313-0-4-2 is a 1/2 inch, 3-way mixing valve made of brass for durability. It regulates the temperature of hot and cold water mixtures in hydronic heating and cooling systems. Despite its weight of around 1.88 lbs, it's a crucial component. Internally, it blends hot and cold water to achieve a desired temperature. https://www.partshnc.com/12-mixing-valve-22cv