The Cast Möbius is a puzzle from Hanayama’s Huzzle Cast series, designed by Dutch inventor Oskar van Deventer. Its main piece is a Möbius strip, the one-sided surface studied in topology, covered by a raised maze. A silver disc moves through that maze, and the aim is to remove it from the strip and put it back.

• BrandHanayama
• DesignerOskar van Deventer
• MaterialZinc alloy
• FinishAntique brass (strip) and silver (disc)
• Pieces2: strip and disc
• DifficultyLevel 4 of 6 (Hanayama scale)

Design

A Möbius strip is made by joining the ends of a band after giving it a half-twist: the result has only one side and one edge. Van Deventer uses this property to build a maze with ridges along the entire surface, through which a disc with two projections resting on the strip moves. Because there is only one side, the path does not behave as it would in a flat maze.

The design dates from 2003; the first examples were 3D-printed, and Hanayama later produced it in cast zinc, a complex piece to manufacture because of the twisted shape of the strip.

What level it suits

Hanayama places it at level 4 on its scale of 1 to 6, although some enthusiasts consider it somewhat more approachable. It suits those who enjoy mazes and those with a curiosity for mathematics.