B+W 46mm Clear with Multi-Resistant Coating (007M) This filter uses our standard B+W F-Pro filter mount, which has a front accessory thread and is made of brass. The F-Pro mount has become thinner. It can be used with wide angle lenses. MRC by B+W is not only an extraordinarily effective multiple layer coating, it is also harder than glass, so that it protects filters from scratches. Manufactured from Water-White Schott Glass