This medium-class lter series was developed in the mid-2000s when digital single-lens reex cameras were popular. Adopting digital multi-coat technology, these lters achieve an overall lter transparency of 99% (protector) with a minimum price premium. The new-concept lter series employs a black-painted frame for reduced reection in the glass, a knurled frame for easy attachment, and other user-friendly features. These lters function well not only with digital cameras but also with lm cameras.