Optical glass, precision grinding and polishing, high-definition imaging; Using multi-layer nano coating process, the lens is waterproof, oil-proof, anti-fouling and scratch-proof; Aviation aluminum frame material; Non-slip gear design, easy to install and remove; The original lens will not be damaged during installation, and the filter can be changed at any time; The lenses are made by nano-coating process, and the color of the lenses is different under sunlight and light.