Product Description:- The device can be used to test battery voltage, avoiding overconsumption of power to affect the starting of your vehicle.- Can be used to detect the temperature in your car, ensuring you are in a comfortable environment.- Clear dual LED display, blue color for voltage display, red color for temperature display, easy to read the number.- USB fast charging port, can charge your mobile phone, cigarette lighter type, plug and play, convenient and practical to use.- 3 in 1 function: car voltmeter, car thermometer, USB mobile phone charger.