High power green laser pointers is a device which can be used everywhere depending on the occasion you are in. it is commonly used at office meetings, presentations and conferences because of the ability it gives you to show the most important points of reports or Power Point presentations. 

Class 4 Laser Pointer is often used also for different activities in community buildings like galleries, museums, exhibitions and other places containing cultural and historical heritage. The reason for choosing this type of laser pens is the ability to point out exact spot of the painting or sculpture. Of course they should not be continually directed to the piece of art because of the damage which the powerful infrared wave can cause. In this way green laser pen can also be used to measure the distance of a building from the point at which is the user.

High power beam laser pointer is also convenient to use in the dark for different astronomy observations, because of its capability to point out the right positions of different galactic bodies such as stars and even near planets, which can be big or smaller. It is also useful for climbing and doing other activities in the wild nature. The wave of the green Laser Pointer pen is suitable for sending a SOS signal when the sender is trapped in the snow-drifts of a mountain.

Laser light is very different from normal light. Safety Laser Pointer light has the following properties:The light released is coherent. It is “organized” -- each photon moves in step with the others. This means that all of the photons have wave fronts that launch in unison.The light is very directional. A laser light has a very tight beam and is very strong and concentrated. A flashlight, on the other hand, releases light in many directions, and the light is very weak and diffuse.

http://www.buylaserpointer.com/blue-laser/p-13.html

The other key to a laser is a pair of mirrors, one at each end of the lasing medium. Photons, with a very specific wavelength and phase, reflect off the mirrors to travel back and forth through the lasing medium. In the process, they stimulate other electrons to make the downward energy jump and can cause the emission of more photons of the same wavelength and phase.

http://www.buylaserpointer.com/blue-laser/p-44.htm

Life expectancy and warranty: Sometimes there will be a spec like "2,000 hour lifetime". This is probably mostly relevant for the expensive Blue Laser Pointer and may be reasonable. Certainly, anything over 1,000 hours is adequate for a pointer used as a pointer within one's (human) lifetime (or until it becomes obsolete). However, any lifetime claim isn't of much value unless there is an enforceable warranty!

http://www.buylaserpointer.com/green-laser/p-2.html