I use this for night riding, especially after an evening at the brewery for open mike night. It works like it says in the manual and does not seem to affect the mechanics of the bike which surprised me considering it uses so many batteries. Its easy to turn on, but hard to find the on off button in the dark. You have to press the off button several times to get it to turn off. That's slightly annoying. When hanging your bike, take care not to damage the device.