Parabox by Jerry Andrus is one of his more famous optical illusions. Hold it at arm's length and close one eye. In a second or two, the concave image of the crate will become convex, or dimensional. Also, when you move the fingers holding the box, it will seem to move independently. A strange and wonderful optical illusion. Simply cut out the image, fold and tape and you are ready to amaze yourself and your friends. Includes three (3) Paraboxes. Use for yourself, give one to a friend, or use one for a bookmark in your favorite Jerry Andrus book.