FAVOLCANO Univeral LCD Display Cigarette Lighter Voltage Digital Panel Meter Volt Voltmeter Monitor for Auto Car Truck (2-Pack) Never worry about your car truck SUV or other vehicle's battery dying again with this simple to use tester! Just plug unit into cigarette lighter and see a bright LED display with your batteries voltage Reliable and easy to use interior tool so you don't even have to get out of your vehicle Prolong the life of your battery by checking it For DC 12V OR 24V CAR. Measuring range:DC 8V-30V+/-%1.2.