Autometer Ultra-Lite II 52mm 8-18 Volt Short Sweep Electronic Voltmeter - 4992

Keep 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.
Installation Instructions