As headlights with USB in this price range can only be recommended. I use it for almost a year and I can report no deficiencies, no rattling even failures. I am very happy, As well as what processing and design. The USB output provides only 500mA. This is as far as I know but especially on the legal regulations that limit the power of the hub dynamo, is not therefore blame the lamp or the manufacturer. In my last year, 2-month tour I have the Always light and a large buffer battery (12000mAh) an iPhone 4s Electrified on which I ran as komoot Navi again. The 500mA ranged only to slow the discharge of the buffer battery. This held as always a few days, so the setup for me was perfectly adequate.
There is the competition brighter bulbs with more bells and whistles. This one has everything you really need. Compared to a halogen headlight or older battery LED lights the progress is enormous. The illumination is pleasant. More natural is always, if you really want. Then you pay but also more.
