Here's how it goes: you place a red, a yellow and a green ball into the narrow tube. Instantly, the balls change places! But that's not all! Next you put the yellow and green balls into the tube, but put the red ball into a small box. Instantly the box is opened- the red ball has vanished from the box and has reappeared in the tube with the other two balls!
Very easy to perform and gets a great reaction every time! The red, yellow and green colors are also perfect for a show with a safety message, too!