Zomei&reg; Ultra Slim Optical Resin Graduated Neutral Density Grey Filter - 72mm Only 4.69mm thickness, Wide-angle lens compatible ultra thin frame. The colour grey filter provides a neutral colour for a more balanced exposure when brightness varies. Ideal for photography and video filming. Glass mounted with high pressure press technology. Use in combination, with one affecting the upper half of the image, the other affecting the lower half. All Materials Used in this filter Meet the Requirements of European Union's standards of Environ Ment Protection-ROHS(Restrictions on Hazardous Substances).