This thermostat is designed to replace Therm-O-Disc style 59T lower thermostats on residential water heaters. It has adjustable temperature settings, pre-set at 120° by the manufacturer. This item is CSA and Ul Listed from the USA and Canada. Meets specification lengths for most American, AO Smith, Bradford White, Craftmaster, GE, GSW, Kenmore, Maytag, Reliance, Richmond, Rheem, Russ, Sears, State and Whirlpool brand water heaters.