Mechanical Rotary Button - Control room temperature by turning the mechanical rotary knob to the desired temperature. It simply ensures ease of use and allows for precise temperature adjustment. 【AUDIBLE CLICK】Experience the comfort of an audible "click" when turning the knob above the current temperature. This feature provides a clear ignition when the heating system will turn on or off. EASY INSTALLATION - With its 2-wire design and potentially free contacts, this thermostat is extremely . It is suitable for use with combined or normal boilers, making it for various heating systems. 【Auto On/Off Control】Designed to detect air temperature and regulate the heater accordingly, this thermostat ensures automatic on/off control for heating. Turns on when the air temperature drops below the thermostat setting and turns off when the desired temperature is reached. WIDE TEMPERATURE RANGE - The temperature adjustment range of this thermostat is 10℃ to 30℃, allowing precise temperature control. In addition, it operates within a wide temperature range from -25℃ to 55℃, ensuring its durability and reliability.