Laser pointers with 405 nanometers wavelength of light are also called blue violet laser pointers. Although it is rarely prefered to the green and red ones, it could be used for what others do, which also reflects the individual unique aesthetic taste. It is probably not as much preferred lasers as an astronomy laser pointer, because brighter colors would make an object more visible in the sky. However it comes down to all other uses such as pinpointing something on the large screen or on the blackboard.
Green laser pointers is now the world's most popular laser pointers, because the green light than red light 6 times more than red light beam significantly, while the price is much cheaper than the blue and yellow. Green pen is the wavelength of light emitted 500-550nm, the wavelength sensitivity of the coefficient table, as is the closest one wavelength. Green is undoubtedly efficient light source, the eye more easily identified. The green light sensitivity of the human eye is higher than a lot of red; the other is green light scattering in the atmosphere more than red light.
Red laser pointers, wavelength 630-670nm green laser pointer is more for longer. The first red pointer was released in the early 1980s. Nowadays, the red laser diode technology has been very mature. More durable, the price is much more cheaper than ever. More easily transmitted red light air, dust, water vapor, so the light path can be seen to need more power. 100 mW red laser pointers probably only about 20 milliwatts, and green. Do remember that red laser pointers are powerful since the light they emit is powerful when it hits a certain object and converges into a point.
Place to note
Now, more and more laser pointers and flashlights sold in the market are class IIIB with a power over 5mW. But when the laser directly penetrates into the eyes, there may be some damage. Especially to some high power laser pointers, diffuse light probably damage the eyes, the focus are more likely to ignite flammable materials. Therefore laser pointers are not a toy, not suitable for children. When operating high-power laser, wear special secure glasses would be safe, especially for the invisible laser. In a word, no matter how much power the laser power is, you need to avoid hitting into your eyes.