The B+W 77mm XS-Pro Clear MRC-Nano 007 Filter is a simple, clear filter with a 1x filter factor and is designed to provide general protection for your lens. To prevent internal ghosting and reflections while providing over 99.8% light transmission, each glass surface includes multiple layers of anti-reflection coating. The Nano coating associated with XS-Pro filters provides an additional eighth layer over the MRC, resulting in an improved beading effect when in contact with water for greater cleaning efficiency. This filter features a thin brass filter ring to minimize the potential for vignetting while enhancing durability and jamming prevention. To further reduce the possibility of vignetting while using this filter, the filter ring's outside diameter is slightly larger than the actual thread size. Nano coating provides an improved beading effect with water for more efficient cleaning.