The Streamlight SL-B50 Rechargeable Battery is designed for select Streamlight products. The battery features a built in USB-C port and charge indicator.FeaturesUse the SL-B50 battery pack to power the ProTac 2.0, ProTac 2.0 Headlamp, and the ProTac 2.0 Rail Mount3.6V, 4900mAh, rechargeable at least 500 timesCharges in 6 hours using USB-C inputBattery charge status indicators around the port: Red for charging, green for chargedIntegrated safety circuit protects batteries from overcharge/overdischarge3.26 in (8.28 cm); 3.0 oz (85.0 g)2-year limited warranty