Stealth Boy (Fallout 3)

The RobCo Stealth Boy 3001 is a personal stealth device worn on one's wrist $$

Gameplay
It generates a modulating field that transmits the reflected light from one side of an object to the other. The result makes the wearer almost invisible to the untrained eye.

Locations
All random-loot safes and ammunition boxes will have a chance of containing a Stealth Boy. Fixed locations include:

Bugs

 * There is a glitch wherein activating a Stealth Boy causes the hair mesh of a character not wearing any headgear to appear on the Pip-Boy, or in random other locations near the character, while in 3rd-person view. This does not affect whether enemies will detect you.
 * There is a glitch where activating a Stealth Boy and then traveling to D.C. ruins on the Duchess Gambit, the effect will still be active as long as 1 in-game hour.
 * Occasionally, if you use a Stealth Boy and then open a save previous to using it and put it in any container (even owned ones), then walk out of the building, it disappears.