1. Optical glass, precision grinding and polishing, high-definition imaging 2. Adopting multi-layer nano-coating technology, the lens is waterproof, oil-proof, and scratch- 3. Made of aviation aluminum frame, the logo is laser engraved and does not fade 4. The original-lens not be damaged during installation, and the filter can be replaced at any time to prevent you from missing the wonderful moment 5. The lens is made of nano-coating technology, and the color of the lens is different under sunlight and light Name:Filter Kit Applicable:for O4 Air Unit Pro Filter model: ND8/ND16/ND32/ND64 Filter (The product appearance and printed words depending on the batch, but this does not affect use) Color: As Shown Material: Optical Glass + Aluminum Alloy Package Contents: 1 * Filter Kit 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.