I just ordered a couple of these. They are incredibly bright for such a small light. They qualify for free Prime shipping when ordered from eToolscity. If you don't have amazon prime, see
this thread. For those that care, it looks as though it is the correct size to fit a 1" scope mount... allowing you to easily place it on a gun.
http://www.amazon.com/gp/product/B000LIOPTS/
Product Description
*9 super-bright LEDs in a heavy-duty, compact flashlight*LEDs last 100,000 hours, emit pure white light--not heat--for 20+ hour battery life*Perfect for glove-box, tool-box, purse or desk drawer. Uses 3-AAA batteries (INCLUDED). 3-year warr*Unique positive-action weather-proof switch prevents accidental battery drain*Anodized aluminum barrel, water-resistant and shock-proof. Also in Cool Blue and Jet Black.This amazing compact flashlight is like a spotlight you can carry in your pocket or purse! NINE light-emitting-diode (LED) bulbs produce a flood of pure, white brilliance but because LED bulbs produce very little heat, three inexpensive AAA batteries will last for over 20 hours continuous. Positive-action switch (click on/click off) won't go on accidentally in car, toolbox or pocket. Heavy-weight anodized aluminum barrel is corrosion- and water-resistant, textured for sure grip even when wet. 3-year warranty.