Increasingly, green laser pointer have become more popular, though they are generally more expensive than their red-colored counterparts ( while the price is much cheaper than the blue and yellow ). Green lasers are simply more powerful than red lasers. They are much brighter and can be seen from much greater distances, even while operating under 5mW. It is possible to enlarge or shrink the laser spot light, widely used in the fields of astronomy, seabed, classrooms, amphitheater, operation and trip out. The power of the laser in a laser pointer is the most important measure of how the laser performs and the type of tasks for which it is suitable. Laser pointer power is measured in milliwatts, which is denoted with "mW" in laser pointer descriptions. The mW rating measures the output of power from the laser. The following chart lays out what the different power ranges on laser pointers mean for their use.