This is a vaguely reasonably priced red LED safety light. I'm somewhat obsessive about having lights at night and wanted to try a few ways to mount extras, and it's reasonably priced for a 5 LED light. On the other hand, I think that, like most bike lights, it's fairly overpriced. But if you want something that's weather-sealed and doesn't require hand-assembly, this is how you have to do things.
I also wanted to see if I could do some hardware hacking on the lights, however, it turns out that it's pretty hard to get one apart enough to hack on it, so I'm not bothering with that.