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.
I started designing puzzles in 1982. That was roughly the same puzzle, but without the 2 cylinder obstacles. The task of this puzzle: remove the ring in the center. I sold 40 of them. 3 collectors sent me the solution. Warning: it is a tricky puzzle!!
