The Klein bottle was first described by Felix Klein in 1882. It can be enjoyed simply as an unusual shape, but it also has unusual properties. It is a one-sided surface which, if travelled upon, could be followed back to the point of origin while flipping the traveller upside down. It might be helpful to think about a Möbius strip. Whereas a Möbius strip is a single surface with a boundary, a Klein bottle has no boundary. Should you want the full details please check out the web. Purchased by John Davenport from Ray Bathke of Village Games, Camden Lock, London.
Made by Walter & Prediger GmbH, Kaufbeuren, Germany. Purchased by John Davenport in 2008 from Ray Bathke (of Village Games, Camden, London) for Euro 20 at the International Puzzle Party 28 in Prague.