I wouldn't typically brag about something I have that's only 1.47" long, but when it comes to a powerful flashlight I want to attach to my keychain or dangle from my belt loop Streamlight's Nano Light actually gets points for what might otherwise be called an
Irish Asian Curse (3.8" average in Korea. Ouch. But holy crap, check out the Congo at 7.1".)
The Nano Light consists of a shockproof aircraft aluminum case housing a 5mm white LED with a parabolic shape to optimize beam performance. Its bulb has a 100,000 hour lifetime. Weight is just 0.36 ounces for easy carry in a pocket, purse, tool bag, or even hooked onto a jacket's zipper. The flashlight's 4 x IEC-LR41 coin cell batteries are included (and replaceable) and provide up to 8 hours of output. Switch the Nano on with a quarter twist of its head, and back to the home position to turn it back off.