American Volt 180'f Radiator Fan 1/2" Npt Ground Thermostat Switch 3/8" Inch Threaded Engine 180'F automotive engine grounding fan switch. 3/8" NPT brass thread-in temperature probe and 1/2" adapter. Activates fan at 180 degrees and turns off at 165 degrees. Universal fit for any application with a 3/8" or 1/2" NPT port. Threads into engine block, radiator, manifold or water outlet.