Limit Thermostat, Normally Closed, Open On Rise, (240F) - 240F and below the electrical circuit will remain closed, 240F and up will open the electrical circuit. Automatic Reset. 3/4" Diameter. For use on furnaces, dryers, fans, dishwashers, limits, ect., U.L.Rated, #L240. These limit thermostats are brand new and made by Napco/Supco Corp.