Steel Ball Thru Glass

The performer displays a small wooden box with holes on top and bottom and a solid steel ball, which just passes through the holes in the box. A glass sheet is placed inside the box, so that it obstructs the hole, filling up the inside of the box. There seems to be no way now for the ball to go through the holes, unless it goes right through the solid glass sheet. Yet the performer does just that - passing the solid ball right through the piece of glass. Includes instructions and original box. Shows mild wear, excellent condition.