Refill Cards for Astor Mental (Stage Version). Includes 5 red backed cards and 5 blue backed cards. Instructions are not included. About Astor Mental For this trick, the magician uses a transparent perspex board, five E.S.P. cards with blue backs and five E.S.P. cards with red backs. Every blue backed card has a matching red backed card. You will have the same E.S.P. symbols on the faces of these cards. The magician slips the blue cards into their slots on the board in an order only he knows. The spectator chooses one by one, in which matching slot the red cards should go, but he only sees the back of the cards. When the magician turns the board around, the blue back and red back cards are in the same order (top to bottom). You can show the trick twice and the order of the cards won't be the same. The cards are not specially prepared.