The SLIM series filter is only 3mm thick (standard UV filters are around 5mm). Thanks to this, there is no fear of vignetting the lenses. The filter has eight anti-reflective coatings, which means that its optical quality is comparable with the highest class Hoya or B + W filters. It is made of optical glass only 1mm thick. The filter is suitable for both traditional and digital cameras, it is black. King filters are made in Japan, which means that their quality is much better than Chinese or Taiwanese counterparts.