2-5/8 In. VOLTMETER 8-18V PHANTOMKeep tabs on the health and output of your vehicles electrical system safely and accurately. With a patented air core meter movement, this gauge operates with category defining accuracy anywhere from 8 18 volts on negative ground electrical systems. Installation is simple and it can keep you from being stranded on the side of the road. Traditional incandescent lighting illuminates around the perimeter of the dial 12 and 16 volt compatible, well suited