Plenum Furnace Limit Thermostat- 5/8" disc diameter -  Normally Closed - Open On Rise - 190 - 150F (40 degree differential). Automatically resets. Housing 2 7/8"H x 1 7/8" W x 3 1/4" L (limit prongs + disc). For use on furnaces, dryers, fans, dishwashers, limits, ect., U.L.Rated. These limit thermostats are brand new and made by Supco Corp. Part No. SHL503