Utilizing a one piece design, a powerful Cree XM-L2 LED, and refined optics, Cygolite's Expilion 850 easily lights up any road or trail. An amazing 850 lumens turn night into day, and run time is 1-1/4 to 9 hours depending on which of the 8 modes you select. It has a high, medium, low, and boost mode, as well as a flashing and walking mode. The unique SteadyPulse mode alerts night time motorists with pulses of light while still constantly lighting your path. Need more run time? No problem! The Expilion uses swappable Li-ion battery sticks (sold separately) to power you through the night. For added convenience, it mounts to helmets as well as handlebars and charges through any USB.