Seeing clear through early morning dawn commutes is easy with the Kryptonite Alley F-800 Headlight affixed to our bars or helmet. With 10 hours of run time on the 140-lumen low setting, we easily get a week's worth of clean commuting out of this light. If the going gets a little dirty on the weekends, the light can happily burn at 800 lumens for a couple of laps at the local mountain bike trails.