B+W 40.5mm XS-PRO UV with Multi-Resistant Nano Coating 010M This Item Includes: B + W XS-Pro Ultraviolet MRC Nano #010M Filter - Plastic Storage Case - B + W Warranty Improves light transmission from about 92% (uncoated glass) to about 98% MC Nano coating makes it easier to clean the filter - water will bead up faster B+W filters provide additional benefits of correction for Ultraviolet(UV) light which can register on film and videotape as a bluish cast and can obscure distant details If desired they can be left on the lens at all times for protection