The one piece design that started it all is brighter than ever with 850 lumens of class leading brightness. Featuring a powerful Cree XM-L2 LED and custom Enhanced Cycling Optics , the Expilion 850 easily lights up any road or mountain. The refined fusion of aluminum alloy and durable plastic ensures a powerful lighting system in a compact design. The included handlebar and helmet mounts, along with its conveniently swappable battery stick provides unmatched functionality and value. Power through the night with spare battery sticks. Technology and Safety 8 lighting modes Bicycle Boost High Medium Low SteadyPulse Special Day Flash Walking SOS SteadyPulse alerts night time motorists with pulses while constantly lighting your path Day Flash enhances rider visibility in peak daylight Swappable Li-ion battery stick spare batteries available USB rechargeable via USB cable or wall outlet charger included Regulated power circuitry maximizes brightness over the battery charge cycle Built-in battery low and charging indicators 2nd generation Locktite tool-free handlebar mount securely clamps to 22 to 32mm diameter handlebars This product includes Expilion headunit, battery stick, USB wall charger, USB charging cable, Locktite tool-free handlebar mount, helmet mount Class leading 850 lumen output Cree XM-L2 LED Enhanced Cycling Optics ECO widens your field of vision and increases your visual profile Water resistant design for all riding conditions 1 15 9 hr run time