Shell material: Hardened PC, reinforced with fine lines on the inside and outside, making the product scratch resistant, textured, anti-fingerprint. Lens material: PMMA, with a light transmittance of 95%. After being coated with AR anti-reflective film, the light transmittance can reach 98%. It is made with AS waterproof and anti-fingerprint film, and AS hard coating. The hardness is 5H, which matches the hardness of ordinary glass and is scratch resistant, providing reliable protection for your camera. Waterproof ring material: Amorphous high-activity silicone Material of the connecting shaft between the main body and the back cover: High-hardness 304 stainless steel Name: For X4 Fully Invisible Submarine Shell Waterproof depth: 50M Product weight: 148g Color: Transparent Material: PC Size: 155x80x85mm Package Contents: 1 x Action Camera Diving Case Note: The package includes only the items listed above; other accessories are not included. Note: Light reflection and different displays may cause slight variations in color compared to the actual product. Measurement error allowance: +/- 1-3 cm.