I was impressed and intrigued when I saw Rudi's caveman solutions, but I've used B&M (and Philips) lights for a while now, and they really are terrific lights. They're only slightly expensive, but they work so damned well that they are a good value. Just hook it up, and it works. The Philips Saferide dynamo light is out of production, so forget that one. I've used a few B&M headlights, and they are all terrific. They have more than adequate overvoltage protection. The light is adequately bright, and the beam shapes are ingenious. The optics are engineered, arguably over-engineered. I wish German law allowed higher power, because the one thing that would be nice is more brightness, but I'm getting by fine. They are not as bright as good battery-powered lights. I prefer the B&M lights, because I prefer the beam shape so strongly. I also prefer dynamo power over battery power.