PWR Trail is a modular bike light. But it's not JUST another bike light. Not only is it a high power headlight, but simply take the product apart and you have much more. A lighthead for other PWR bike and camping lights, plus a PWR Bank to charge devices that is also the battery for all products in the PWR range. The PWR Trail outputs a max 1000 lumens, can run for up to 300 hours on Eco Flash mode, uses an elliptical beam for broader road coverage, can be mounted both on top or under the handlebar (mount under your Garmin), or your helmet, incorporates twist mode operation (turn the light on and off twisting the lighthead - no buttons) and gives you the option to program your brightness and runtime through our ModeMaker app. Fits handlebars: 22.2mm - 31.8mm Ø.