... .Lens Thickness: 2.2mm 3.Idea for metal polishing Polycarbonate Night vision goggles ( Our model No. SG9000 )DescriptionMaterial: High quality PC & PlexiglassLens ... 2mmAanti-impact, Anti-splash, anti-scratch Features Full eye protection Night vision goggles, anti-impact, anti-splash, anti-scratch Idea for metal polishing ... , metal ores or stones crushing and so on Polycarbonate Night vision goggles