After I've tried first one, ordered 6 more to give as presents to friends, and everyone liked it.
Previously i used similar keychain which charged from sun, they died pretty quickly(not very green) and was harder to maintain, this one could be charged anytime including time when it's really need, no matter it's day or night.
And one more good thing, it have a switch which make it possible to turn it on when needed and leave, no need to keep your finger pressing the button.
Crank may not look solid but so far I didn't break it.
I keep it on my keys as it's small enough to be used as keychain flashlight.