Brainwave deck
Brainwave deck
https://www.zaubershop-frenchdrop.com/brainwave-deck-zaubertrick?c=134/?sPartner=MAAZ050618
The magician places a deck of cards on the table locked into the case. A spectator thinks freely of a card and names it. The magician takes the deck opens it with his hands and shows how a single card is turned face up. Clearly it is the named card from the spectator, which will also be the only one with the back different from the others.