This battery and charging system monitor displays the condition of your battery and charging system instantly. It protects the engine computer and 12-volt accessories from damaging surges when jump starting or recharging. You can easily plug into the vehicle's cigarette lighter or power receptacle to monitor battery and charging system voltage. It has an LCD screen which displays the measured voltage with a bar graph to indicate battery charge level and it also has color-coded LEDs which quickly identify the battery's charge status. The head pivots for easy viewing and angle adjustment.