1. Material (lens): optical glass + aluminum alloy 2. CIR-PL filters allow you to remove unwanted reflections from non-metallic surfaces such as water, glass, etc. 3. It can also make the colors more saturated, look sharper and have better contrast 4. This effect is used to increase the contrast and saturation of the blue sky and white clouds 5. Ultra-thin frame compatible with wide-angle lens 6. Diameter: 37mm 7. Weight: about 30 grams
