Mid 1970’s. Great trick, think reverse 3 card Monty! The spectator is asked to take a Dollar bill from their wallet and place it under one of the three cups on the numbered board and then switch them while the Magicians back is turned. The Magicians not only easily identifies the cup the Dollar is under but later recites the entire Serial number digit by digit! Rare trick in excellent++ condition and with original 2 page instructions sheets.