A set of Klein Bottles made by Allan Bennett at the Science Museum in London. The museum seems as much one of the history of display as it is of the things that are displayed, and the mathematics gallery is one of the most confused, despite a delicious selection of exhibits. There is therefore a lot of visual confusion surrounding these wonderful didactic models.
Usual process to view the stereo images (look back a few posts for suggestions if you are new to the blog).
And Happy New Year!