Just got a Fenix E15, and am uncertain if I'm going to keep it. It seems to only use the bottom 2 threads to keep the head on, and doesn't engage the rest unless screwing down the head fully. However I cannot fathom ever needing to screw it all the way down to use. In order for it to not turn on in my pocket/fondling, the "Hot" logo on the head needs to match up at the end of the "FenixE15" logo on the body, doing this i can see the top of the rubber o-ring on the head. Not sure how "waterproof" this is... I carried this little guy in my pocket for a night out with some friends, and the plastic lens already has a nice gouge. The black coating on the body seems fine with no signs of wear, but I'm wondering how long that lens is gonna last. Know I shouldn't really expect much from a $30 light, but I mean, sheesh. Really like these tiny lights, but not if they're all gonna be like this.