Built in USB-C port Charges in 6 hours Charge status indicator The Streamlight SL-B50 protected Li-Ion battery pack with built in USB-C port for charging on-the-go. Use the SL-B50 USB battery pack to power your select Streamlight flashlights. Fits select Streamlight flashlights that take SL-B50 battery packs. Charges in 6 hours and features charge status indicator. Integrated safety circuit protects the battery from over discharge and overcharge.