Item Type: Lens Filter Color: As Shown Material: Aluminum Alloy + Optical Glass Package List 1 x UV protective mirror 1 x CPL Polarizer 1 x FLD Purple Filter 1 x Filter Storage Bag 1Aluminum Material: Aluminum alloy frame, made of high quality aerospace aluminum alloy, high toughness, anti deformation, corrosion resistance, good processing performance. 2CPL Polarizer: CPL is a widely used filter to eliminate unnecessary reflections and most reflections on non metallic non spherical surfaces. It is generally used in landscape photography. When shooting, the sky is bluer, and when shooting water, it can eliminate reflections on water surface, so that the scenery under the water can be photographed, making the whole picture clearer and more transparent. 3Filter Function: Purple filters are often used in landscape shots to create a dreamy purple effect, UV filter can reduce the blue tone caused by ultraviolet light, improve the clarity and color reduction effect. 4Waterproof Performance: Excellent waterproof performance, 2 layers of waterproof film, make the lens surface smooth and not easy to stain, effectively protect the lens, suitable for photographers to create in bad environment. 5Lens Coating: 18 layers of double sided coating, 16 layers of anti reflective film,2 layers of waterproof film effectively reduce the reflection of filter surface, long exposure light reflection caused by glare and ghost.