Thermo Cube Thermostatically Controlled Outlet

I don't know if the ThermoCube has changed any over the years, but I have one controlling a bank of four 15 watt bulbs that keep the pressure tank for our cottage water supply from freezing. As best I can recall, it's at least 10 years old and still working. We have a remote reading thermometer in the insulated "dog house" with the tank for monitoring.