K&F Concept square ND1000 filter kit of very high quality, consisting of a glass filter, a filter holder, and lens adapters for the filter holder. The package comes in three parts: 1. A bag with the metal adapter rings for different lens diameters. 2. A box with the filter and its leather carrying case. 3. A box with the filter holder. The adapter rings allow us to attach the filter holder to any lens, as we offer a large number of different diameters. They are made of black metal and are well-finished. Each ring is marked with the corresponding diameter. The filter is made of glass, made in Germany. It is a 100x100 mm square ND1000 filter, 2 mm thick. It allows us to remove 10 stops of light for perfect long-exposure photography in daylight. The example photo I posted was taken at 30" at midday. I love the flexibility you can get out of this filter. The filter comes in a leather case with a tissue paper lining the inside. The case is rigid enough to protect it properly. The glass doesn't scratch easily with fingers and doesn't attract dust. The filter holder is metal, with the filter insert made of a very hard plastic. It fits two 100x100 filters and also 100x150mm gradient filters without any problems. The adapter ring is attached using a very handy metal tab. In several tests I've done in different lighting conditions, I haven't noticed any residual light entering through the space between the filter and the filter holder. The photographs have a slight magenta tint that's easy to correct in editing, but it's not at all exaggerated. With the complete kit and the price, it's a fantastic filter to experiment with and achieve excellent results. I'm truly delighted and enjoying it a lot. I recommend it!