Dubbed the Nightfire, this incredibly small flashlight from River Rock Designs is just slightly longer than its battery and let it blasts away with 100 lumens. And impressively it is powered by just a single AAA battery.
The key to this is the LED light, which offers effective power project to over 50 yards, and the ability to light up a 30×30-foot room. It has a one hour run time, which really isn’t bad for the battery and it has rubber O-rings to help make it water resistant. For $29.99 it can certainly cast a whole lot of light.