B+W UV filter MRC nano master 40.5 mm. The classic among protective filters blocks the disturbing UV component from daylight. The invisible UV light occurs more intensively in pure sea air and in high mountains; it can lead to blurring and a blue cast. The color-neutral UV filters ensure more brilliant images. The filters can remain permanently on the lens and protect against dirt and damage. The high-quality MRC nano coating offers optimum reflection reduction.