Feature 1 Block Wavelength: Light pollution reduction filter blocks the wavelength of light from common light pollution sources, allowing the picture to show true colors and high definition picture quality. 2 Optical Glass and CNC Precise Molding: Optical glass, no color cast, to ensure high definition image quality. CNC precise molding, non slip pattern, thin gold thread design. 3 Double Sided Multi Layer Coating: The light pollution reduction filter is waterproof, oil proof and scratch resistant to protect your camera lens. 4 Ultra Thin Frame Design: The ultra thin frame minimizes vignetting from wide angle and telephoto lenses. 5 Applicable Scenes: Natural night filter light pollution filter is great for nightscapes and astrophotography.Item Type: Light Pollution Reduction FilterMaterial: Optical Glass, Aluminum AlloyNumber of Coating Layers: Double Sided 18 Layer CoatingFrame Thickness: Approx. 3.15mm / 0.1inColor: As Pictures Shown Package List1 x Filter1 x Filter Box