Caixa de interruptor de cristal

Endless effects are possible. For example, borrow a $20.00 bill from a spectator. Ask him to fold it and place it into the box for safe keeping. The box is hung around the spectator's neck, in full view. You concentrate, then write a serial number on a piece of paper. When the spectator removes his money from the box and reads the serial number of his bill, the number exactly matches your written prediction!

The box can be checked by the spectator, even after the switch is completed. The switch is invisible, and is done without you touching the box. Deluxe model designed for years of professional use.