American Volt Electric Radiator Fan Thermostat Switch 1/8" 1/4" 3/8" 1/2" Inch NPT Temperature Sensor Thread-in Push Probe (1/8" NPT, 160'F On - 145'F Off) Brass thread-in or push-in probe thermostat kit. Closes electrical circuit at temperature and passes power. Various temperature ranges to suit your project needs. Measures liquid coolant, oil, or water temperatures etc. For engine block, radiator, cylinder head, manifold, outlet tube