The GC015 Eyelet Battery Indicator is the latest addition to our accessory offering for NOCO Genius Multi-Purpose Battery Chargers. The GC015 is a smart battery indicator device that monitors a batteries health when not connected to a battery charger. It displays battery health from 0-100% by pulsing the batteries current state-of-charge in order to minimize back current draw. A perfect accessory option that lets you know when your battery needs to be charged. Works with models G750, G1100, G3500, G7200 and G4.