Filter 37 MM MC-UV K&F Koncept KU04K&F Concept KU04 37mm MC UV filter. The MC UV filter is specially formulated to effectively eliminate most of the harmful UV rays, while maintaining the full naturalness of colors. It also provides reliable protection for your lens from dust, pollen and scratches, and with a light transmission rate of 99. 2%, it leaves your image pristine and clear. Manufacturer K&F Concept Model KF01. 022 Thread diameter 37 mm Thickness 3. 6 mm Light transmittance