Ultra-thin filters adopted a special technology of double sided, multi-coating, lens employs high quality Japanese optical glass, which assures high transmittance and highly smooth surface. Meanwhile, the frame using high quality aluminum frame (with thinness of only 3 mm), it´s the thinnest in the world so far. This ultra thin filter fit perfect even on super wide angle lenses to avoid vignetting and reflections. This filter cuts UV-light under 395NM. Additionally, superfine dull polishing and elaborate knurling make sure that the frame will not blanch because of repeated rotation. All materials used in this filter meet the requirements of European Union´s standards of environment protection---ROHS(Restrictions on Hazardous Substances), they contain nothing hazardous. Furthermore, screw thread in front of the frame makes it easy to install the lens cap and other accessories. Ultra thin, only 3 mm: Minimize vignetting effect on wide angle lenses Multi coating on both sides of the filter High quality optical glass for high transmittance (>98,3%) and highly smooth surface with low reflection (0,5%) Protect the lens from dust, damage to the front element Hard waterproof and oil repellent coating on outer side Easy to clean
