I'm such a nerd. I made a chainmail klein bottle. (If you don't know, a klein bottle is kind of like a mobius strip but with a tube instead of a strip of paper. It does funny stuff such that the inner surface connects with the outer surface.)

Also, I sized it to fit dice. So I can keep my dice outside of it. (A klein bottle is a closed surface that contains no volume.)

I'll scrap these pictures and post better ones once I find enough dice to stuff it with.

Made (mostly) of galvanized steel that I wrapped and cut myself. If someone really wants it, I might part with it for a hundred bucks or so, though it took a lot more time than would make that a reasonable price. I liked doing it.