Features: LED display cigarette lighter electric voltage meter for auto car battery. Car battery voltage display. Powered by car cigarette lighter charger (DC 12~24 V). Installation: Insert the jack of the product into a cigar socket. This digital gauge displays the voltage of batteries in the car. With the high brightness of the LED(light-emitting diode), there is no difficulty in seeing the display. Installation: Clean the cigar socket. Insert the jack of the product into a cigar socket. Display Type: Digital Operating Temperature: -10 to +80 Celsius degree Accuracy Class: high Item Type: Battery Testers Voltage: DC12-24V When the engine running (do not drive), the LED display: Between 13.5 TO 14.5 (12V CAR) Between 26.0 TO 28.0 (24V CAR) With the engine off, and nothing turned on the LED display: Greater than 12.0 (12V CAR) OR 24.0 (24V CAR)(for reference only) Measuring range: DC 8V-30V%1.2 Specifications: Color: Black Material: Plastic Size: 70*40*30mm Packing content: 1 x Electric Voltage Meter Note: Please pull out the device when you leave your car, do not use the device for more than 2 minutes in 24V cars, or it will burn out.