MICTUNING WATERPROOF Voltmeter 12-24V DC LED Digital Display Vm Universal for Automobiles Motorcycle Truck Boat Marine - Red Input voltage: 12V-24V DC; LED Digital Display; EASY to install, works great for checking Voltage Measure voltage: 6-30V, great mini voltmeter to monitor your vehicle battery status Size: 1.4'' x 1.4'' x 0.5''; Interface type: Anode and Cathode; Meterial: Environmental protection engineering plastic shell Mounts in a 1-1/8" hole in panels up ,0.25" thick, a nylon retaining nut holds the meter in place Universal for: Marine cockpits, caravan applications, trucks, 4x4s and RV's. Your best choice to know where your battery is at voltage wise