A plastic ball is shown with two strings completely threaded through the ball. In addition a small clear plastic box is shown with a hole on each side. The ball is put into the box and closed. The box is placed in the hands of a volunteer and the ends of the strings are tied around the closed hand. It looks impossible for the strings to come free without untying the knots or opening the box, but a few magic movements from you and the strings come free, leaving the box and the bead intact.
This is a cute little prop that can fit in your pockets and comes boxed.