CPL filter: CPL filter for insta360 GO 3S, multi-layer coating, waterproof, scratch-proof, dust-proof, oil-proof, protect your camera lens from all-round damage. It can eliminate reflections from non-metallic surfaces, such as glass and water, when shooting. It is often used to shoot scenes behind glass, clear and transparent water, and underwater creatures. It also enhances color and contrast, making the sky bluer and the water clearer. It is especially suitable for shooting white clouds and blue sky Optical glass lens: Each filter is made of high-definition optical glass, which has no effect on image quality. After multiple grinding and polishing, it forms a low refractive index to ensure the restoration of the true color of the image for color-accurate photo shooting Aluminum alloy frame: The aviation-grade aluminum alloy frame is laser engraved with multiple oxidation finishes to prevent light leakage or ghosting, ensuring that each filter has been rigorously tested and will not add extra burden to your thumb camera or interfere with the normal shooting, weighing only 1.8g Easy installation: Threaded interface design, quick installation, stable fixing, no need to worry about falling off during shooting With storage box: Comes with a filter box, which is convenient for storage and also protects the filter, making it easy to carry Specifications: Material: Aluminum alloy + glass Weight: 1.8g Size: 21.7x3.7mm