The B+W 40.5mm XS-Pro UV MRC-Nano 010M Filter is a general use, clear filter that helps to absorb ultraviolet light and reduce the bluish cast of daylight. No additional coloration or contrast is provided, allowing you to pair this filter with others.

The UV filter is also useful as a general protective filter to leave on lenses at all times. Filters help to reduce dust and moisture from reaching your lens element and provide additional protection in case of drops or situations where scratching could occur.

The Multi-Resistant Coating (MRC) is both an anti-reflection coating as well as a protective surface. It helps to increase light transmission by reducing reflections, scattered light, and ghosting. Additionally, it offers greater protection to the filter substrate and stays cleaner for longer than uncoated filters. The Nano coating associated with XS-Pro filters incorporates an additional 8th layer over the regular MRC and results in a better beading effect with water for greater cleaning efficiency.

B+W filters are constructed from high quality Schott glass for increased optical clarity and color fidelity. This filter features the XS-Pro Digital mount which is specifically designed for DSLR use with wide angle and zoom lenses. The filter ring is made from brass for durability as well as jamming prevention. 

Note: This filter ring's outside diameter is slightly larger than the actual thread size, and because of this you may be unable to attach the lens manufacturer's bayonet-mounted lens hood to the lens while using this filter. This is dependent on your specific lens and how thick the front rim of the lens is; with thinner, low-profile lenses usually being affected more.