Impossible Japanese Puzzle is a 3D printable version of a wooden puzzle.
The challenge is to move the ring on the string from one side of the main puzzle body to the other side.
It might seem impossible at first but there is a way to do it.
For the impatient ones here is a link to YouTube video that shows the solution to the puzzle:
Follow the pictures for the assembly process.
The part was designed in inches.
The base of the puzzle is 3 inches long.
The string is about 12 inches long.