Chinese rings | devil's needle puzzle

A puzzle involving disentangling a set of rings from a looped double rod, originally used by French peasants to lock chests. The word "baguenaudier" means "time-waster" in French, and the puzzle is also called the Chinese rings or Devil's needle puzzle. ("Bague" also means "ring, " but this appears to be an etymological coincidence. Interestingly, the bladder-senna tree is also known as "baguenaudier" in French.) Culin attributes the puzzle to Chinese general Hung Ming (A.D. 181-234), who gave it to his wife as a present to occupy her while he was away at the wars. The solution of the baguenaudier is intimately related to the theory of Gray codes.

Gray code | Habiro move