Thermostat is a device used to adjust the temperature of display cabinets, where 1 stands for the lowest temperature and 7 stands for the highest temperature. Therefore, the thermostat 7 has the highest temperature. This is because the design principle of the thermostat is to adjust the working state of the heating or cooling element by controlling the current or resistance, so as to achieve the purpose of controlling the temperature. Therefore, when the thermostat is set to 7, it will provide the maximum current or the maximum cooling effect, so that the temperature of the display cabinet can reach the highest.