The lower thermostat for double element water heater thermostat can be used on most residential electric water heaters. Thermostats are set at 120 degree Fahrenheit and are adjustable between 110 degree Fahrenheit and 160 degree Fahrenheit. The reliance thermometer includes a safety energy cut off, that cuts off all power to the heater should internal tank temperature reach 190 degree Fahrenheit. It fits water heaters with Apcom, Robertshaw and Therm-O-Disc thermostats. It is made with high quality construction for premium performance and long lasting use.