SHAPE PHOTOMAIN FUNCTION & FEATURE 1.There are four function buttons on the main control board,Website:http://www.china-energymeters.com, which are on/off, setup, up and down. 2. Open or close the refrigerator freely and setup the inside temperature. 3. Setup the protect gears of battery voltage in the car according to the actual situation, in order to avoid over discharge of the battery. 4. Setup the compensation value of the temperature sensor when leave factory, make sure the accuracy of the temperature testing.5. Freely switch between ℃/℉ based on the client's habit. 6. Constant current output control of LED lamp and Hall element control the switch of the LED lamp.7. Automatically detect of open circuit and short circuit of the temperature sensor.8. Manually switch the automatic temperature control mode and forced cooling mode9. Function of avoids power source reversal connecting. TECHNICAL PARAMETER1. Operating voltage range: DC 8V~30V2. Operating temperature range: -30℃~70℃2. Temperature control range: -18℃~10℃3. Display resolution of temperature measuring: 1℃4. Display resolution of voltage measuring: 0.01V5. Refrigerator compressor: 12V DC convertor, 24V DC convertor WE CAN OFFER TAILOR-MADE DESIGN OF DIFFERENT FUNCTIONS FOR OUR CUSTOMERS.