reviewed: “K&F Concept Nano-X PRO Series UV Filter 77mm, Slim Flagship MCUV Filter Protective Filter” The filter came well packaged in elegant outer packaging. Even its exclusive appearance aroused curiosity about the filter. After opening it, an elegant, very cleanly crafted leather filter protective cover is revealed. This has a folding mechanism that closes securely and cleanly with a magnet. On the side of this protective cover there is a fabric flag. If you pull on this, the filter comes partially out of the cover via the pull-out function, so that it can be removed very easily and without risk of damage. The filter is packaged again in a foil bag upon delivery. Inside the packaging there is also a microfiber cleaning cloth. After completely unpacking the filter, you can attest to its equally high-quality and clean workmanship. The filter is free of manufacturing or material defects. The thread of the filter screws onto the lens very easily. The manufacturer states 0.01 mm processing accuracy. You can feel this during assembly. Absolutely nothing wobbles here. This means that neither wide-angle nor telephoto lenses are impaired in their original performance. Everything works perfectly. The result is impressive. From now on, my high-quality telephoto lens will be very well protected and, thanks to this UV filter, which guarantees 99.9% light transmission, it will be optimally equipped for fantastic shots without any loss of image quality. The filter has a double-sided 36-layer nano-coating. The 0.15% reflectivity of the filter ensures the aforementioned good light transmission. This greatly reduces stray light and prevents further glare. The filter is also waterproof, dirt-resistant, and scratch-resistant. The filter is also extremely lightweight with a very thin brass frame. This frame shows the type, manufacturer, function, and serial number of the filter. Conclusion: A high-end filter from K&F that impresses with extremely good workmanship and high quality. A clear purchase recommendation despite the very high price. I rate the product 5 stars. Thank you for reading my review, I hope it was helpful to someone.