RioRand Universal Cigarette Lighter Car USB Port Cell-Phone Charger Digital LED Display Voltmeter Thermometer Auto Gauge 3in1 12 V 24 Volt Battery Voltage Tester Temperature Monitor Meter Powered by RioRand Advanced Technology USB Output Voltage: DC 5.0-5.1V; USB Output Current: 0-2.1A, built-in fuse Voltage measuring range: DC 8-40V, DC12V/24V; Temperature measuring range: -10 ~ 80 c Function 1 : Car battery voltage monitoring, 12V cars/SUV, 24V trucks/buses Function 2 : Universal USB charger, cell phones, digital cameras, tablet PC, for Apple/Android ;Function 3 : In-car temperature measurement, -10 ~ 80 c