Description: -small size design provide convenience for using and intalling. It combines three functions of time, temperature and voltage. Three functions can be switched at any time. A total of 4 display modes: display only time / display only temperature / display only voltage / time temperature voltage alternate display. With manual correction of temperature error, the setting range is -5~5C. With a backup battery, the power down time continues. Specification: Material: Plastic Size: 40mm*13mm*16mm Package Includes: 1 Piece Car Digital Voltmeter Module 1 Piece Power Supply Cable Note: In the alternate display , the dd option can be used to select whether to display the temperature or voltage, and the dd:0 state displays the time + temperature + voltage. The time + voltage is displayed in the dd:1 state. Dd: 2 shows the time + temperature