While I think the value of these step up rings are amazing, I don't think the same could be said about the quality. They seem to be very well made, but at the same time don't function properly.

In my case, I have the Sony F 1.8 11mm lens which has a filter size of 55 mm and bought the K&F nano x true color VND at 67mm. After purchasing the 55 mm to 67 mm step up ring, I found out that the step up ring tightens nicely onto the lens, but not at all on the filter itself. No matter how much I tried to tighten the filter on, it would always remain loose.

For a normal ND filter, this wouldn't be that big of a problem, but since I had a VND, I was unable to utilize the lever on the filter since the entire filter itself would rotate. This meant that I would have to use two hands to control the VND filter. I tried using both step up rings to see if one was just defective, but they both had the same results.

After purchasing a much more expensive step up ring that was made out of brass, the issue went away.

TLDR; if using a VND filter, the connection between the step up ring and VND will be loose, unsecure, and freely rotating.