Mystic Scope by Tenyo

Show four coins, and allow your spectator to secretly choose one. With your back turned, have him insert the coins into four separate frames. When you peer through the Mystic Scope, you can instantly divine the chosen coin. In another presentation, ask a spectator to secretly write down a friend's name on a slip of paper. Let others peer through the Mystic Scope, and they'll be able to reveal the chosen name. This presentation is great for parties. At the end of your performance, nobody else will be able to unlock the power of the Mystic Scope, due to its clever construction.