Looking for replacement rings

[Asriel Torrien]

I purchased dome riveted aluminum mail, and I want to purchase some "Upgrade" rings. The only problem is I can't seem to find any stainless or mild steel dome rivet rings in a size of 13mm(That's what my calipers said the size was at least) If you know of a place where I could purchase these I would be extremely grateful for your help.

[Asriel Torrien]

Oh, ok. Thank you!