Viridian released a green laser aiming device for the Ruger LCP called the Reactor 5.

The unit is lightweight at only 0.78 ounces, which includes the battery.  The unit can be set for a constant beam or pulse.  Battery life is listed as one hour for constant on, two hours for pulse mode.  MSRP is $219.

The Reactor 5 comes with a pocket holster that can activate the laser when drawn.  To use this feature, the user would turn on the laser and then insert the gun into the holster.  While in the holster, the laser is off.  When drawn, the laser comes on instantly.

The Reactor 5 is different from the Reactor TL, which is a white light designed for the LCP.  However, both units appear to share similar housings.