Limit Thermostat Switch, Normally Closed, Open On Rise, (320F) - 320F and below the electrical circuit will remain closed, 320F and up will open the electrical circuit. Auto Reset. 3/4" Diameter.  For use on furnaces, dryers, fans, dishwashers, limits, ect., U.L.Rated, #L320. These limit thermostats are brand new and made by Napcous Corp.