Mini LCD Voltmeter with Alarm Mini LCD Voltmeter with Alarm designed for battery voltage monitoring. 10-30V DC Mini LCD voltmeter with pre-programmed low voltage warning flashing back light Surface mount LCD digital panel meter. Features: compact surface mount design which can be mounted on a dashboard or any other flat surface; large 3 digit LCD display with back light; pre-programed Low Voltage Alert logo indicator with flashing back light; reverse polarity protection; 2 wire operation; weather proof PVC casing design; easy D.I.Y installation.