Chesapeake Black 2" Ammeter Gauge (-60 to +60 AMPS)Perimeter-lighted Black dial with stylish Blue and White graphics, polished stainless steel bezel, contoured White pointer and domed glass lens.An ammeter indicates the current flow through the battery charging system. A "zero center" ammeter, during chargine, shows a (+) positive reading indicating the current is flowing to the battery (charge). A (-) negative reading indicates current flowing away from the battery (discharge).2" - Hole Size: 2.0625" (53mm)Specifications:. Anti-scratch glass lens. Perimeter lighted back light. 12 VDC negative ground. Can be adapted for 24 VDC systems. Factory P/N AP9530*Sold as an Individual**Gauge Cover not Included