Interesting. It doesn't make pure water, it makes sport drink. It uses the salt and sugar of a sport drink to create the osmotic pressure to suck the water in. Rather expensive, though.

And yah, that's what a mini light is for, to help you find your big light. The mini light is small enough so that it's always with you. Don't want comments like "Is that a flashlight in your pocket or are you happy to see me?"