B+W ND Filter 806 ND106, MRC Nano 100x100 mm, 6 f-stops. High-quality finely ground and polished special glass forms the basis of the ND square filters. This guarantees the necessary optical quality and ensures that a high-quality lens is not compromised. The ND filter effect is created by coating the glass surface. Uniformity is important because only then is light evenly attenuated over the entire visible area, resulting in optimum color-neutral images. Using this manufacturing technology, a combination of coatings ensures the highest quality filter lenses and, in addition to the filter effect, reduces unwanted reflections via an anti-reflex system (7 layers per filter side).Finally, a water-and-dirt-repellent nano-coating is applied. This scratch-resistant coating protects the whole of the square filter. It also facilitates easy cleaning and maintenance of the filter.