High-quality UV Protective Filter, designed for superior lens protection Made from Schott B270 glass, offering up to 99.4% light transmission Durable frame crafted from high-quality aviation aluminum with a uniform surface gloss 3.1mm ultra-thin frame design with knurling for easy grip and no vignetting Double-sided coating with 24 layers to reduce reflection and increase light transmittance Dual protection feature, being both waterproof and oil-proof for handling harsh environments