Hi, I have one of these, for the price, I think it's okay. It's thicker than you might imagine, at EXACTLY the same thickness of two CDs or DVDs stacked upon one another. Appears to be made of rubber with some kind of metal bracing inside so that once you bend it, it stays in place. The light is an annoying purple hue, a sure sign of a cheap LED. The front bezel and LED lens seem like they're fine, but on the back, the battery cover feels like it might break after too many removals, and the switch is where I'd bet money the unit will first thing to fail. It feels really cheap.
Ultimately I don't use this light because I like to read with the kindle out of its case, and this whole design is predicated on the idea that you'll have your case on the kindle, so you can slide it down in between the back of the unit and the cover.
I haven't found a clip-on light yet that I'm happy with, either the clip is too wide for the screen bezel or doesn't have a good enough grip. Always something, huh?
Hope this helps a little.