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.