It's the classic bullet-style laser pointer shape, except formed into a perfectly Beautiful green laser. And being able to easily carry such an item on your Keyring is, shall we say, quite brilliant.

Features:
1) Keychain attachable laser pointer
2) Extremely bright green laser at 532N. M wavelength
3) Output power: 5mW, 10mW
4) Momentary push button switch
5) Solid, heavy duty construction
6) Takes 3 button style batteries (included)  
7) Can be used for skypointing, projection on low clouds, signalling, detecting explosives
8) Dimensions: Approximately 2.9" x 0.5" dia.  
9) Weight: about 5 ounces