2 INCH WIDTH X 2-1/8 INCH DEPTH X 5-5/8 INCH HEIGHT SIZE; UL, CSA, AGA APPROVAL; HIGH AND LOW LIMIT, BOILER, STORAGE TANK, DUCT APPLICATION; 120 TO 240 VOLT AC VOLTAGE RATING; HORIZONTAL/VERTICAL MOUNTING; 100 TO 240 DEG F OPERATING TEMPERATURE; COPPER