Looks and works as expected .

I bought this UV protection filter for my Sony 28-70 kit lens, it good fit and great protection filter. I can not tell the difference between filter and no filter in the most shots. It is also pretty light. I am really satisfied with this good made and high quality UV filter.

I only use these to protect my front element. Their cheap enough not to worry about damaging them. If it gets damaged, I'll throw it away & get another. Glass appears to be flawless as expected.

Have 4 of these in 77mm, 67mm & 86mm. For the price, they're good, have no noticeable image quality issues, easy to wipe the water off of. They do scratch fairly easy so depending on your usage you may need to replace them yearly, and when used without a lens hood in sunlight or directly into the sunlight you get blue ghosting (could be worse, but I remove it when shooting towards the sun).
But quality vs cost, these are definitely the best option.

These filters are worth what I paid for them. Coatings are beautiful with absolutely no defects. Easy to clean without smearing. Great clarity.

I had used a popular UV filter before. It's not bad. Only under certain conditions would there be glare or aberration. For the most part, it worked fine. But it still bugged me. So I ordered this K&F UV filter. WOW! What a difference! The glass is SO clear you can't tell it's in the housing! And that is how clear my photos became with it on! Definitely worth the price difference! All my filters are now K&F brand. The quality is outstanding!

Very happy does the job.

I purchased this for a camera that I seldom use. It still is a valuable collectors item that I want to keep in excellent condition and that means I needed to protect the lens. I only have filters with the Zeiss "T" coating constructed of German Schott glass on the cameras I use frequently, because I consider them the best multicoated filters that I can afford but, I cannot spend that kind of money for a camera I use infrequently.
Any camera that is threaded to accept a filter deserves the protection that comes with a mounted filter in front of the actual camera lens. I would rather risk damage to the AR coating on a filter that can be easily replaced than risk damaging the actual lens on any of my cameras from cleaning, and exposure to airborne dust or chemicals.
This brand of filter came carefully packed and the filter holder included with the filter is well designed and provides excellent protection for the filter when it is not on the camera lens because I am using a different type of filter. This filter has multiple AR coatings on both sides of the filter and after comparing the results of identical pictures with the same camera using this filter and one of my prized and now unaffordable Zeiss "T" filters I can say that I can see no difference in the results. I am sure an optical lab could document some differences, but in the real world, I can see no differences when comparing the test pictures I captured through this filter and the Zeiss filters I have used.
This design works so well, I will slowly replace the older non Zeiss filters I have on my older lenses and cameras with these newer designs.

Great quality pictures

This is an excellent UV filter. It really works to darken the blue of skies.