15 watt Single beam system with 4.5Ah NiMH battery. This system can do it all. Mount it on your handlebar for those times when you need the light on your bike, or mount the light on your helmet so the light goes where you look. Includes everything you need to use both ways. Features: New 4.5 Ah Nickel-Metal Hydride Smart battery pack, New Multi use battery pack can be mounted on bike for handlebar use or placed in jersey pocket or in a hydration pack for helmet use, New SurLok Connectors, 15watt halogen bulb with variable light levels, 10-step fuel gauge with low battery warning and 15 minutes reserve @ 6 watts, MicroBrute Charger, CamLok™ QR handlebar mount and Multi-position helmet mount, Auto-Shutdown increasing battery life Bulb SoftStart prolonging bulb life, Commuter Safety flasher, Walking Mode, S.O.S. and Beacon, System weight: 22 oz (mount, head lamp and battery). Burn Times: Up to 5 hrs burn time in Walking mode, 3:30 @ 6 watts, 2:25 @ 10 watts, 1:45 @ 15 watts