The Nor-Lake 135805 Heater Control Thermostat provides reliable temperature control for compatible commercial refrigeration equipment. This thermostat monitors operating temperature and switches the heater circuit on or off as needed to maintain the selected temperature range. Its 80 D specification is designed for compatible Nor-Lake applications requiring the specified control. Replacing a worn or faulty thermostat can restore proper heater operation, maintain consistent temperatures, and reduce unnecessary cycling. It is a practical replacement component for compatible Nor-Lake refrigeration equipment in commercial foodservice environments.