I can't picture a ring that would be able to snap on and off. The read side of the disk should be perfectly flat without any type of ridge. Nice to hear you were able to make a copy.
Edited: Had a hard time finding info on the product. I did find something on D Skins (not rings). You are correct, they do snap on. The site does not provide a great deal of information or make any mention of imbalance issues.
I'm not saying they're bad, but merely from what I read I would not use these on my equipment.
Read about them here: