Double shock-proof strength over a normal glass filter Waterproof, oil and fingerprint proof and easy clean surface Ultra-thin Nano Multicoating that retains superb image sharpness as well as delivering true color with zero color cast R5 rounded corner design making insertion into the Filter holder much easier Haida Red Diamond 100mm 0.9 3 Stop Medium Graduated ND Nanopro coated Glass Filter 4x6 100x100mm. Haida’s latest line, Red Diamond filters, promises all the advantages of the Nanopro filters and are engineered to be the toughest line of filters in Haida's current offerings. The Red Diamond filters feature a shock-and-scratch-resistant design, making them ideally suited to the harsh challenges of outdoor landscape photography. Haida Red Diamond Filters feature an ultra-thin Nano Multicoating that retains superb image sharpness as well as delivering true color with zero color cast. The Red Diamond series is double the strength of a normal glass filter, which provides for a low risk of accidental breakage. With a waterproof, oil and fingerprint proof Nanopro coated surface, this filter is easy to clean and ideal for use in harsh environments due to its scratch resistance. Quality and convenience come together with the R5 rounded corner design making insertion into the Filter holder much easier. A Medium Neutral Density Grad is used to filter the sky with minimal impact on the land. Ideal when elements like rooftops and mountains protrude into the sky, balancing out the exposure throughout the frame. These filters are rectangular in shape to provide more flexibility to move the filter up or down within the holder to precisely position the graduation line, for ultimate create control.