Honeywell Zone Valve, 120Vac, Three Way, Diverting, 1/2″ Sweat, 4 Cv, 20 Psi Maximum Closeoff Pressure, Manual Opener, 18″ Electrical Leads, Spring Return to Port A, Port A Normally Closed, 40-200 Degree Fluid Temperature Range, Brass Body, Stainlkess Steel Stem, Brass Seat, EPDM Rubber Packing O-Ring, Buna-N RUbber Ball Plug, Includes Integral SPDT Changeover Aquastat Controller