NiSi 100X100mm Square Neutral Density Filter, IR ND4(0.6), ND 2 Stops 100mm System Optical Glass for 52mm,55mm,58mm,62mm,67mm,72mm,77mm,82mm Lens,Compatible with Lee Cokin Hitech Singh-Ray Can be used for Canon 16-35,Canon 24-70,Nikon 24-70,NiKon 70-200 and other 52mm,55mm,58mm,62mm,67mm,72mm,77mm,82mm lens,compatible with Lee Cokin Hitech Singh-Ray and other brand holder The optical glass (H-K9L) is cured by a fine annealing process and a double sided optical grinding and polishing process help to ensure a quality high definition rating. NiSi filters are precision cut, polished and optically processed to allow for extreme flatness and high parallelism for the highest quality glass, image quality and image crispness. Nano attenuation coating,Water&oil repellent coating,Ultra low color shift,Ultra low reflection NiSi square IR ND filters are not only coated but we have also added a Japanese fire-proof foam gasket to ensure there is no light leakage.