Product name: Polarizer CPL 

Frame material: aviation aluminum 

Lens material: German imported optical glass 

Frame height: 5.3mm Caliber: 40.5/37/43/46/49/52/55/58/62/67/72/77/8  

The full name is: Circular-Polarizing Filters, that is, circular polarizing filter Mainly used to eliminate polarized light, increase color density, deepen the sky blue, highlight white clouds, and eliminate non-metallic surfaces such as glass or water. It can also reduce the soft focus caused by atmospheric fog in landscape photos, but it does not change the tone balance of the entire picture.