Mobius gear
From Wiki introduction to Möbius strip:
The Möbius strip or Möbius band (…) is a surface with only one side and only one boundary component. The Möbius strip has the mathematical property of being non-orientable. It can be realized as a ruled surface. It was discovered independently by the German mathematicians August Ferdinand Möbius and Johann Benedict Listing in 1858.(Neatorama)
A… Möbius HAT??
I like nerdy things…
Moebius gear! The Möbius strip (also spelled Moebius) is a surface with only one side and only one boundary component....