The ProTac 2.0 Rail Mount is a 2,000-lumen tactical weapon-mounted flashlight that uses a proprietary Streamlight SL-B50 protected Li-Ion rechargeable battery pack. The ProTac 2.0 Rail Mount features a tactical tail cap switch switch for momentary or constant on operation and three different user-selectable programs. The Streamlight SL-B50 charges directly via USB-C port in the body of the battery. The battery is keyed to ensure proper alignment of the charging port. USB-C cord included.