1. Multi-layer coating filter, high transmittance and high light to restore the true color 2. Using professional optical glass lens, the image is clearer 3. Protect your expensive lens from dust and scratches without degrading photo quality. 4. Material: Optical glass 5. CPL Filters: Increases color saturation, creating deep, rich scenic images. Helps to reduce the amount of light entering the lens. 6. ND Filter: You can get more freedom to control aperture and shutter, bring more exposure methods and creative space for photography creation, and effectively prevent overexposure. The number behind ND represents the ability of the ND mirror to block light.