1. Imaging-grade optical glass, high-definition picture quality, hard and scratch-resistant, waterproof and oil-resistant 2. With a large area of magnetic surface, tightly adsorbed on the lens, easy to deal with a variety of sports scenes 3. Aluminum alloy frame, sturdy and durable, laser engraved text, no color loss, no fading 4. Thin and lightweight design, the lens off the axis lock no problem 5. Does not block the host lens field of view, the shooting screen transparent without dark corners 6. ND filter, light reduction and long exposure 7. CPL polarizer, restore the original color of the wonderful 8. Material: aluminum alloy + glass 9. Size: about 22.1 x 15.9 x 2.2mm 10. Weight: about 1.1g 11. Description: only the filter, does not include other items in the picture