Before buying this, please consider the Nightcore Tube, 9.6 grams functional, 45 lumens, flexible functions, RECHARGEABLE, IP65 dust and water resistant, impact resistant, 1 hour runtime on High, 5 colors to choose from.
It's never (AFAIK) come on in my pocket and drained the battery. MicroUSB charging, which I have literally everywhere. I'm done with overpriced batteries, particularly ones that fit only 1 or 2 items. I'm skeptical about that...