The magician shows 3 cards, each with a drawing of a screw on it. One red, one yellow and one green. He then removes three screws in the colors of the cards from a plastic jar. These screws are fitted with nuts. Ask the spectator to shuffle the cards face down. Once the cards have been returned, he asks the spectator to choose one of the three cards that will remain on the table. The magician now places the screws inside the plastic container and covers it, then rotates the card and guesses the color of the chosen card. The spectator turns the card over and confirms that it is correct. The magician then indicates that he had the help of the screws. He uncaps the jar and drops them on the table. Incredibly, the screw corresponding to the color of the spectator's card is the only one without a nut on it.