Tenyo - A Whole New Hole

Magician displays 2 cards, each card has a round hole at the center.
One card is chosen by spectator and the spectator makes a magical gesture towards the other card.
In the next moment, the round hole transforms into square hole!
The card is handed out to spectator immediately to make sure it is a rigid square hole!

Special material and unique ideas allow you to perform this mysterious effect easily, without hassle.