1、The module equipped with a measuring sensor. 2、You can set control mode for automatic control. 3、High temperature start-up cooling mode: When setting start temperature value> stop temperature value, when the detected temperature ≥ start temperature, the relay is closed and the refrigeration equipment is working; when the detected temperature ≤ stop temperature, the relay is turned off and the refrigeration equipment stops working. 4、Low temperature start-heating mode: When setting the starting temperature value <stop temperature value, when the detected temperature ≤ the starting temperature, the relay is closed and the heating device is working; when the detecting temperature ≥ the stopping temperature, the relay is disconnected and the heating device stops working. 5、With indicating light to indicate the working condition.