One of the audience picks a card from a deck.Put the chosen card in a card case with its face down, and strike the case on the table.In a second, the color of the card’s back and the case changes.The color of other cards also changes.Features:Boxing Match has been updated!Adding a story, the whole performance has become more visually appealing phenomenon.Instruction is provided through a video.You can watch the explanation video by scanning the QR code on the back of the package.