The Duke TA-21 food warmer thermostat regulates heat output in compatible commercial warming equipment by controlling the electrical circuit according to its temperature setting. Specified for single-phase equipment, this thermostat is supplied without a knob, which distinguishes it from complete control assemblies. It is relevant to restaurants, cafeterias, and catering kitchens that... https://partsfe.com/thermostatkp-14-x-12-c36-for-duke-part-ta-21/1-TA-21.html