1: The lens material is PMMA, with a mittance of 95%, and the mittance can reach 98% after AR anti-reflection film coating, AS waterproof and anti-fingerprint film, AS hard film, hardness of 5H, comparable to ordinary glass hardness, scratch-, Added anti-reflection anti-fog film and anti-hanging water drop film coating to maximum mittance during , and strive to achieve clarity equivalent to shell-free . 2: The shell is made of {1803 high temperature , oxidation } PC, with 10 fine lines inside and outside, making the product scratch , textured, anti-scratch and anti-fingerprint Button material: stainless steel 316. Waterproof ring material: amorphous high-activity silicone. Material of the connecting shaft between the main body and the back cover: high-hardness 316 stainless steel Compatible with magnetic quick-release base Function: Prevent camera from bumping, wear- and scratch-, 360-degree , seamless panoramic image stitching above and below water, complete elimination of blind spots, waterproof to 60 meters Material: PC Color: parent Package Contents: 1 x Dive Case Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.