What are the standards for a good laser pointer?

Laser swords are divided into 4 grades according to their output, and the weakest are [Class I, Class II, Class IIIA, Class IIIB. In the past, Class IIIA toys were also sold in the form of keychain toys, but due to the danger, they are not seen anymore. 20000mW laser pointers for conferences and presentations can be obtained from stationery manufacturers, etc., but they are all Class II high powered laser pointers. Use the green super discount laser pointer because of the high visibility. This is because products commonly used as laser pointers also have legal output restrictions, so even if the output is the same, the more "easy-to-see" colors are more meaningful. There is also a view that, in terms of the use of people with congenital color vision defects in surgery and visual recognition, green lasers are easier to detect than red lasers. DPSS (Diode Pumped Solid State Laser) products have become popular for green leather pens at low prices. However, due to the large number of optical equipment and other parts, the electronic circuits are complex, and they are generally more expensive than red laser pointers. A tendency. Depending on the product grade (price range), there are differences in output stability and shock resistance when dropped. Especially because the temperature characteristics are more serious than the red laser pointer, some low-priced products cannot be irradiated for more than a few hundred seconds, and some products clearly state that they cannot be irradiated for a long time.