✔️ This voltmeter measures DC Voltage precisely from 8V to 16.0V. ✔️ Mini size with 3-digit LED Digital Display. ✔️ Simple connection, easy to use. Waterproof. Connect directly to the battery to display the real-time data of the current voltage. The positive pole is connected to the red wire and the negative pole is connected to the black wire. The power cord is about 100cm long. ✔️ Displays "LLL" when the voltage is lower than measuring range; displays "HHH" when the voltage is higher than the measuring range. ✔️ Widely used for cars, motorcycles, bikes, substation automation, distribution automation, test equipment, voltage regulator and so on.