Tips: the same appearance of this pen, there are three light sources for the choice of Oh, respectively, red light, green light instructions blue and purple light instructions show a single indication function.

The brightness of the light: green> red> violet (dark green and red light can see the beam. Blue-violet light can not see, violet light is relatively short, relatively large spot, pro mind carefully shot, But can test money)

Light stability: green light <red light = blue violet light (green light affected by the climate, the use of colder conditions, the need for preheating)

This is the black box set price