When you open the incoming package, you notice that the packaging is very high quality. The brand is very careful with the presentation of its products and the materials are of high quality. The filter holder and the adapter ring are made of metal and the filter holder has a sponge-like area, the function of which is to seal with the filter without allowing light to pass through. Once the filter holder is in place, it can be moved easily. The quality of crtsal 100x100 is very good, with highly polished edges. The filter holder has two slots for square filters, but the advantage is that the ring screwed onto the lens can be screwed to another round filter, for example a polarization filter. The picture is very good in my opinion. As with the brand's round filter, the sharpness isn't lost, I didn't notice the color cast, anything that can be edited during development is appreciated. The ND1000 filter included in the kit enables long exposures in strong light. The sample photos are photos taken on a cloudy afternoon with and without filters. Those with filters were made with an exposure time of 20 seconds.