B+W 62mm HTC Kaesemann Circular Polarizer with Multi-Resistant Coating New generation of Kaesemann High Transmission Circular Polarizer with 1 - 1.5 f-stop loss. Before up to a 3 stop loss. This filter uses our standard B+W F-Pro filter mount, which has a front accessory thread and is made of brass. 24mm full frame lens use. MRC by B+W is not only an extraordinarily effective multiple layer coating, it is also harder than glass. It protects filters from scratches, and it is also water and dirt repellent, thus facilitating filter maintenance.