Nickel Metal Hydride (NiMH) Battery.PREMIUM Benefits Robust Perfomance - more consistent performance under load Higher Current Capabilities - ideal for high drain applications Compatible with all NiMH ChargersKey Features:Premium Quality Ultra High Capacity AA Size rechargeable Nickel Metal Hydride (NiMH) BatteryExact replacement for standard AA size battery in all the devicesProvides long runtimes per charge