I first purchased the K&F Nano Series filter for one of my lenses. I believe it was for my Nikon 80-200mm F2.8 D ED lens. That lens produces really sharp images at distance and is not a close focus lens, even noted by Nikon. I bought the lens used and it came with a beat up UV filter. I was getting ghosting and when I removed the filter the ghosting was significantly reduced. I ended up buying several more for my other lenses. I also use B+W filters too. Well made filters as well, but a little more costly. The K&F is by no means a $100 filter, but for the price it does what I need. I especially like the nano-coating that resists grease and water. Worked well when I was photographing at the beach. Easy to clean the sea mist off without smearing.
We really do not need UV filters anymore with digital since UV does not interfere with the sensor like it did with film. I simply use them to keep from having to clean the front elements of my lenses all the time. I feel reducing that to a minimum will prevent potentially scratching the element. I know there are a few schools of thought on this topic, but I just do what I am comfortable with. From what I read and can tell the filter is glass and not plastic, which is nice these days. I have them on all my lenses now and happy with them.