Uses three cards that have a punched hole. They are fixed together by a bolt threaded through the holes. A spectator signs on the middle card. When the signed card is pushed between the other cards, the card slides. That means, the hole on the middle card moves over, and now it has come close to the signature. At the end, the bolt is removed from the card and audience finds that the hole has been moved. Everything is examinable after the effect.
An explanation DVD is supplied.