A long long time ago (.. I can still remember ♫) there were these old bottle caps. My parents still have 2 or 3 at home from soviet times. They look kinda like this:
What are those called? Ar there some keywords to find them? It took me at least 3- minutes to even find this image (and it was in middle of completely unrelated images down on something like the third image-search page). Or, the best option, where can I buy a box of these?
P.S. I know that the image is from "flip-top" wikipedia page, but what I am looking for is a cap, that is independent from the bottle itself.