Largest Klein bottle

The largest Klein bottle measures 41.75 inches (106 cm) high, 24.5 inches (62.2 cm) wide and has a circumference of 64.37 inches (163.5 cm). It was designed by Clifford Stoll (USA) and built by the Killdee Scientific Glass Company (USA) between 2001 and 2003. The bottle is on display at the Kingbridge Centre in Toronto, Canada, a conference centre owned by scientific equipment entrepreneur John Abele (USA). Abele commissioned the bottle as a symbol of the "boundary-less environment" he hoped to create at Kingbridge.

A Klein bottle is a single-sided object with no edges, first theorised by German mathematician Felix Klein in 1882. If you lay a piece of paper flat on any part of the bottle, you can slide it across the surface until it is on the opposite side from where it started without it ever crossing an edge. Technically speaking, the Klein bottle on display at the Kingbridge Centre is what's called a three-dimensional immersion of a true, four-dimensional Klein bottle, as it has an intersection where its "spout" passes through the wall of the bottle.