Aquat Fahrenheit Dispaly All-Purpose Temperature Control Controller Home Brew Auqarium Air Condition Thermostat with Sensor 2 Relay Output STC-1000 110V 10A Switch the modes between cool and heat Temperature calibration, Fahrenheit Dispaly Control temperature by setting the temperature setting value and the difference value Refrigerating control output delay protection Alarm when temperature exceeds temperature limit or when sensor error.