All numbers are in a slide. Slides from left to right. Under number 4 is the free hole. A difficult puzzle, but it can be solved. Assignments on the back of the puzzle.Material acrylic.
During an International Puzzle Party (IPP) I received a drawing with 2 puzzlesfrom Serhiy Grabarchuk. I made it. Assignment on the back of the box see photo 3.Material 9 cardboard pieces.