Really nice adjustable ND filter. Threads onto lens easily without binding or any issues. The adjustment ring is smooth and works well. There is no X at any point. No color shift at all. Excellent optical quality. Recommended.

Update: Based on a question from Amazon, the orange tab is indeed removable, allowing use with a lens hood on my 16-35mm lens. The screws on the tab require a T3 Torx bit for removal. Once off, the knurling on the ring edge provides more than enough grip to turn the VND as long as you can fit your fingers in there. You will, of course, lose that cute orange accent.

Original: This variable ND (VND) filter is being used on a NIkkor 16-35mm f4 zoom lens. Overall good performer so far. The filter threads are smooth when attaching to the lens itself or to other filters and comes off without binding (so far). I have a NISI VND (67mm) that gets used with my other lenses and this K&F filter compares favorably. The filter frame is aluminum and should stand up to some abuse.

When used alone on the lens there is no vignetting at any point from 16-35mm at f4 to f22. The view frame corners are clear and crisp at all settings with no "X" effect at any setting combination; no vignetting was apparent on the digital pictures (of a blue sky) either. When used in combination with another filter (NISI clear filter, thin frame) however, there was the faintest vignetting at all four corners under almost all lens/f-stop settings.

The filter has an orange tab used to dial-in your desired ND setting. While each setting (ND2, 4, 8, 16 and 32) are marked with dots on the outer filter ring, there isn't a positive indentation for those positions. The tab moves the ND ring smoothly in both directions. That tab does, however, prevent me from keeping the lens hood on during use of the VND, so keep that in mind.

The filter comes with a nice leather semi-hard case with a magnetic catch that should provide good storage protection if you don't already have a separate filter case.

Only con, for me, is that, while there are some threads on the outside of the filter, they aren't really deep enough to accept what seems to be an 82mm lens cap. Could be part of the design to prevent vignetting, but my NISI VND take a lens cap no problem so I'm not sure what the issue is. Shouldn't be a problem, but still...

Overall a good filter at a good price.

A company known for its quality, this is another high quality filter. It fits both branded and off brand lenses as I have both and there is no difference in how it treads on, it has the perfect fit in both. I take pictures occasionally of water birds by lakes, rivers and some ocean birds as well. This is indispensable for reducing harsh light off water surfaces and helps in keeping the photos from washing out.

Got the 72mm and an adaptor ring for using it with smaller lenses, for more flexibility.

The adjustment ring on this variable NF filter is solid and sturdy, and big enough to comfortably move with my large fingers. It is fantastically clear at all stops and images look amazing!

This is an impressive filter from a high quality company.
It comes well-packaged and has an excellent, sturdy storage case for keeping it safe.
Many times I have found multipurpose products to be lacking in some quality. That's not the case with this ND filter. It takes the place of five filters and each setting gives high quality results. It's also a great choice because it frees up valuable space in my camera bag.
I can't see any degradation in image quality with this filter. It doesn't make sense to have an expensive camera and lens and then put inferior glass in front of that. My image quality is still top notch with this filter.
This filter won't work with a lens hood due to the lever but that's not a problem for me.
I absolutely recommend this ND filter.

This is a great quality filter. The glass is solid and the housing feels well constructed and easy to use. The image quality is fantastic. I don’t have another filter that I’ve compared this too, but with the initial usage of this so far, there’s no need to try another one.

This is a great filter. I'm bummed about the orange nub on the filter because I can't use my hood with this filter now, but it is still a great lens filter that I will use often.

This was a good quality filter that was easy to use and turned out great I would recommend this

This K&F neutral density filter is a very nice quality lens filter. It has a nice fit and works well. the difference in the photo quality with the filter on is very noticeable.

This lens filter is well made and durable. I tend to be all thumbs and therefore I drop things, this filter is robust. I am far from a professional photographer, but I think I found my brand. It is a great filter and really allows me to get shots that show the true beauty and colors. I find this to be a versatile filter that can be used in a variety of settings.