I ordered the K&F Concept Nano-X PRO series UV filter to use with the Pentax HD DA★11-18mm F2.8 ED DC AW lens. I generally use my high-quality lenses without a UV filter. Ultimately, every additional piece of glass in the optical path impairs the quality. But in dusty weather or even in the rain, using a UV filter is definitely a good idea, as you can then dry the filter with a cloth or remove any dust. If the filter gets scratched, the front element of the lens is still undamaged. Now, to the filter. The K&F Concept Nano-X PRO series UV filter comes in rather elaborate packaging. The filter is in a pouch, part of which is even made of real leather. The closure is magnetic. There is a strap on the side of the pouch. If you pull this strap, the filter slides out of the pouch. Also included is a cleaning cloth and a cardboard stand (?). I don't understand the point of this. Perhaps it's intended for display purposes by dealers? The filter is "Made in China." There's a German importer's address on the box. The filter easily attaches to my Pentax HD DA.★ 11-18mm F2.8 ED DC AW lens. There's nothing to complain about. The Pentax HD DA★ The 11-18mm F2.8 ED DC AW lens is not shaded by the filter. The workmanship of the filter is also really good. I took a few test photos with and without the filter and did not notice any negative effects. Under normal conditions I don't think the image result will deteriorate much. There might be problems with light reflections in backlit photos if the sun is at the right angle. But that would be a general problem with filters on lenses. Conclusion: The filter is really good. The current price of €149 for the 82mm filter is certainly anything but a bargain. Ultimately it doesn't make sense to buy a lens for around €1500 and then screw a cheap filter onto the lens, which then leads to poorer image quality. I give the filter 5 stars.