I’m not talking about a ring with some Bitcoin logo slapped on top of it.
I’m talking about a plain-looking ring such as the One Ring from The Lord of the Rings, that you can order and buy physically, which has some sort of clever means to store your Bitcoin on it in a secure manner. That is, some way to store the private keys in some kind of memory that’s embedded inside it, or something like that. So that you can literally wear your Bitcoins at all times.
I’ve been unable to find such a thing, but I find it highly appealing as you are unlikely to lose such a thing.
PS: There is no requirement for the ring to make you invisible.