2 WIDTH X 2-1/8 DEPTH X 5-5/8 HEIGHT SIZE; UL, CSA, AGA APPROVAL; BOILER, STORAGE TANK, DUCT APPLICATION; 120 TO 240 VOLT AC VOLTAGE RATING; HORIZONTAL/VERTICAL MOUNTING; 40 TO 180 DEG F OPERATING TEMPERATURE; COPPER; AQUASTAT[R] BRAND