Force Shopping Bag - Net

The performer explains that inside one box there is a gold coin or ring, while the others have nothing in them. Four spectators now freely select a box each, just dips his hand into the bag which you can see right through, and pulls out a box. The last box left is for the performer. The four spectator’s boxes are open to reveal nothing inside. When the performer’s box is opened, it is found to contain the gold ring.