One thing I've always wondered is why Nikon did not make more filters compatible with the HN-12 hood. The original 52 mm. polarizer had an oddball thread, something like 60 mm., on the outside, and that elegant two part hood fit nothing else. I would have thought they might have made some other filters that would use the same hood, but I see no sign that they ever did. Nor have I ever seen an adapter that would allow the hood to be put on anything else.
The Nikon polarizer filter also has stops so it doesn't keep rotating, so it doesn't need an exposed stationary part to hold on to when putting on or taking off.