For GoPro 56 PGYTECH Deep Diving Snorkeling Filter Waterproof Case 1. Product material: optical resin; aluminum; ABS&PC 2. Coating process: nano multi-layer coating 3. The lens is made of advanced optical resin material, which is light and simple, strong in resistance, good in light transmittance, and wear-resistant 4. Lightweight aviation wear-resistant aluminum frame design, high-precision CNC machining 5. Black ultra-fine matte frosting process to prevent reflection 6. Narrow frame design, no dark corners to provide effective fill light for the picture 7. Reserved water holes to prevent bubbles from forming when shooting underwater 8. Portable design, reserved lanyard buckle 9. Suitable for 4-25 meters underwater freshwater or saltwater waters, can effectively reduce the influence of green tones or green tones caused by green algae, and correct color deviation problems. This model needs to be used with a waterproof case (not included) 10. Net weight: 11 grams