A transparent case is shown and inside the magician places a banknote as a prize. One key only opens the padlock with which it blocks the exit of the banknotes, the other keys do not open the padlock. Now the magician mixes the right key with the other four and places them in a glass that allows the audience to mix.

Finally the five are placed on the palm of the magician's hand and four spectators are asked to choose one of them. One at a time the keys taken from the public are inserted into the lock but none of them open. The last key, the one left to the magician, will be the one that opens the lock. Everything can be examined.

The padlock is supplied with 5 identical keys and the case to hold any banknote. Paper instructions inside.