Two-way on-off low voltage valves consist of an actuator and valve assembly for controlling the flow of hot water. Use this valve in closed loop hydronic systems that do not contain dissolved oxygen in system water, such as fresh water from frequent source of makeup water. Valve designed for cycling (not constantly powered on) applications. Brass Body, Brass Seat, Stainless Steel Stem, Buna-N Plug / Ball / Disk, EPDM Rubber Packing