Ebay listing 130998200118 from grommets...Cheers
Your eBay item number as a clickable link grantro:
electrical junction box grommets << click
These are 1/2" electrical junction box grommets. Soft rubber which lets them slip into place. They won't work on older cymbals which have holes less than 1/2". I've used them on cymbals which do have 1/2" holes such as this old Avedis. Here's an illustrated example:
[img]http://black.net.nz/cym2014/grommet-out.jpg[/img]
[img]http://black.net.nz/cym2014/grommet-in.jpg[/img]
The rubber grommets do reduce the inner diameter available to fit over the plastic insert, so you may not be able to use some stands with the modern one piece plastic cymbal protectors. You can get around that, but the down side is that if you want to use your cymbals on backline kits you might need to bring your own "retro" cymbal protectors as well as your own cymbals. I found I had to switch to the "retro" curved metal washer style. That goes on first, then felt, then cymbal, then top felt (optional). You don't need any plastic on the shaft itself because the grommet handles that. If you have retro posts (6mm vs 8 mm) then you can optionally add one of the thinner plastic sleeves. And I've seen online (but not purchased) some 6mm but otherwise modern one piece cymbal protectors.
Here is a different approach I haven't tried yet. These are for tarps and tents (in brass) and have a separate part which locks in place:
tarp grommets << click
Since I haven't tried these I'm not sure how much they reduce the effective inner diameter. Maybe somebody else has experience with these.