Type: Car clock/Thermometer/Voltmeter Material:Plastic Color:Black Light Color: Blue/red/green Quantity:1pc Input voltage: 5 20V (to use the voltmeter function, the input voltage is at least 7V or more) Voltmeter range: 7 20V, error ± 0.1V Temperature measurement: -50 to 130 degrees Working current: 30MA Item Size:4*1.3*1.4cm/1.6*0.5*0.6"(L*W*H) 1.There are three functions,Set time, temperature and voltage 2.Three functionscan be switched at any time. 3.Total 4 kinds of display modes. 4.Only display time/only display temperature/only display voltage/three of functions alternate display (Note: in the alternatedisplay mode, can choose whether to display the temperature or voltage,through the dd option under the condition of dd:0 display time + temperature+ voltage. dd:1 display time + voltage. dd:2 display time + temperature). 5.Manual correction function with temperature error, setting range of -55. 6.With a backup battery, power down time to continue to go. Package includes: 1 x Digital Car 3in1 Meter