Scopes are mainly divided into the following three categories: Telescopic sight, Collimating optical sight, and Reflex sight. Among them, telescopic sights and reflective sights are the most popular. The above two types of sights are mainly used during the day, so they are collectively known as white light sights (day scope/sight), in addition to night vision sights for night sights (night scope/sight), is to add night vision devices to the above two types of sights, and according to the type of night vision devices, it can be divided into low-light sights, infrared sights (and can be subdivided into active infrared and thermal imaging two categories).