With this review I am referring to the product "K&F Concept Nano X-Series UV Filter 82mm Schott-Glas B270 28 Layers MC Super Slim", which I purchased in January 2023 and now after a few weeks I would like to share my experience. Background: As should already be generally known, UV filters are no longer bought for UV protection these days, since no damage from UV radiation is to be expected due to various lens coatings. The UV filters are therefore usually only used as lens protection to protect the front element of an expensive lens against dirt and damage. In the event of damage, it can simply be replaced. I therefore primarily wanted protection for my Sigma 24-70mm 2.8 Art and my Sigma 35mm 1.2 Art, which have the same filter diameter. Positive: I could not detect any noticeable change in image quality in my tests. Both the sharpness in my test photos was the same as without a filter and I could not see any artefacts or disturbing light reflections. There are also several independent tests that compare the quality of UV filters - the K&F Nano-X does not show any major loss of quality, at least not in these either. The ribbing on the outside of the filter is also very positive. This is (at least subjectively for me) actually helpful and creates more grip. The box is also stable enough to safely take the filter with you to the place of use. Neutral: What is also often criticized with cheaper filters is the canting of the filter, which means that it can no longer be loosened. With my copy I could see differences between my lenses, but the filter always ran quite smoothly. At least I couldn't find any major problems. As you can hear in the attached video, it makes noises on my 35mm 1.2, but doesn't tilt at all. Negative: I didn't notice any points that would make me devalue the full number of points differently. If this review and the attached pictures and videos were helpful, I would be happy to receive positive feedback ("helpful answer" button). If you have any questions, please leave them on the product page. I'll try to answer them there too!