Where can you buy powerful green laser pointers?

Do you know how astronomers buy green laser pointers? As we all know, the green laser pointer is also called the finger star pen. Because of its bright beam and strong resistance to stray light interference, it is more and more used for teaching/astronomy pointing stars, fixed-point guidance, etc. It is the majority of laser enthusiasts/astronomy It is the first choice for enthusiasts and outdoor activity enthusiasts. It can also be used as a high-end gift for friends and relatives. The narrower the bandwidth, the more expensive it is, but the human eye cannot tell the difference in bandwidth at all. Therefore, friends who are financially struggling choose the power below 50mW, and the price is A laser pointer below 100 yuan is more suitable. In addition, the power consumption of Laser pointer is generally relatively large. Based on the principle of environmental protection and saving, it is also necessary to have a good pair of rechargeable batteries. The price of 50mW power is not very expensive, only a little over 100.The green laser pointer is often used in teaching. It is a modern teaching mold and equipment. The teaching laser pointer is the third-generation writable laser pointer. Teachers, trainers, and lecturers all touch when they make teaching demonstrations and project demonstrations. To this kind of embarrassment, it is necessary to explain while operating the computer, and the movement is restricted, which is very inconvenient. How to completely liberate users during teaching and demonstration, and truly realize "where to go, where to talk, where to talk, and where to point". The emergence of laser pointers really solved these problems and freed the speaker completely.