Provides fan operation control and high limit protection on all types of forced air heating systems. Used in line voltage, low voltage or powerpile applications. Electrical ratings: Fan - 14 amps @ 120v, 7 amps @ 240v. Limit - 8 amps @ 120v, 4 amps @ 240v. L4064A - Economy O.E.M. type. Helical bimetal sensing element; no metal cover. L4064B - Standard replacement type. Helical bimetal sensing element; manual/automatic fan switch, metal cover. L4064D - Spiral sensing element for shallow insertion. Manual/automatic fan switch, metal cover. L4064W - Helical bimetal sensing element and bimetal heater switch which delays fan operation for 20 to 90 seconds after call for heat. Used in most high-efficiency furnaces and other applications to eliminate cold draft problems upon system startup. Manual/automatic fan switch, metal cover.