*Note from the laser tech - if you do buy one of these high power lasers and hope to have it adjusted. It cannot be done on all models. Some do not have the adjustment resistor. Others start mode hopping when brought down to safe levels - this causes the beam to go all over the place. When in doubt - buy a sub 5mw laser from a trusted source.
I personally use a 3mw 532nm (green) laser on my p90. This puts it in the class 3R rank according to the new laser classes that have been revised if i read correctly. (
http://en.wikipedia.org/wiki/Laser_safety) I also have it on a thumb trigger so it is not always on and try to keep it aimed as center mass only. Also this is primarily used in our indoor venue so the chance of some one being injured due to viewing it with optics is reduced as magnifying optics are pointless at these ranges.