The VA-1A is a FAA/PMA approved instrument which features a discharge warning light to act as an early warning device alerting you as soon as discharging begins. This is critical in giving the pilot as much time as possible to reduce electrical load and extend the life of the battery in flight. Also, by monitoring load currents to .1 amps the pilot can check important aircraft functions such as retracts, boost pumps, transmitter power, pilot heat, navigation lights, transponder, strobes, and any other electrical equipment. The VA-1 can replace your existing amp gauge. It is backlit for night operation and operates on 12 or 24 volt systems. Available with internal or external shunt. Wt. 9 Oz.