DROKxae; White LED Digital Display Automotive Clock Voltmeter Temp Thermometer Gauge Feature:Multifunction, Time/Voltage/Temperature,3in1 Power Supply voltage: DC 7-30V ( with anti-reverse protection ) Measuring temperature: -55 to 125c Measuring voltage: Range 0-200V DC , Accuracy 0.1V Clock: 24-hour, the battery backup is available 2 years