B+W 52mm 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. 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, and it is also water and dirt repellent, thus facilitating filter maintenance. 1x Filter Factor. No Exposure Change Glass surface includes eight layers of anti-reflection coating. No Effect on Image Manufactured from Water-White Schott Glass