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I have found a trick in my card wallet but cannot remember what it is called or even how to perform it. I will have to buy it again to receive instructions.
The wallet consists of 3 cards 2 of which have holes,1 square the other circular.
There are also 2 brass discs, one with a square engraved on it the other with a circle.
Can anyone help me with the name of this trick so I can order it.

Thanks in advance.