So, appalling scam aside, everyone knows what a Klein bottle is or what it does? First I've heard of it, and neither Stoll's site or the Amazon listing shed any light on the topic...just in-jokes.
It is mainly a joke/gag product for mathematicians, or a cool office decoration.
Nothing you would buy without the background knowledge.
But second sentence in the listing:
> Like a Möbius strip, this Klein bottle has only one side. In addition, a Klein bottle has no edge - the connection from "inside" to "outside" is smooth, and the bottle has no lip.
