American Volt 180'f Turn-on Electric Radiator Fan Grounding Thermostat Switch 3/8" Inch Npt Universal fit for any automotive vehicle and 12V electric fan. Activates up to (2) fans by grounding at pre-set temperature. 180'F turn-on temperature, 165'F turn-off temperature. 3/8" NPT thread-in brass probe. Probe typically threads into radiator, water outlet or manifold.