"The Top Performer" TPD. Double line break - line voltage - heating thermostat for series 20,25,30 Baseboard, Rating 22A, 125 or 250 V- AC, 18A. 277 V- AC Range: 35 degrees to 90 degrees Fahrenheit. Ceilheat - Knoxville, TN. Never used sat on shelf since 80's in original box