A small white block is marked with a spectator's initials. The block is slipped into a wooden tube. The performer turns the tube end on to the spectator to show that the block just fits into the tube. The performer allows the spectator to view the block through the first window in the tube. With the aid of a small wooden rod, the performer then slowly pushes the block along the length of the tube, thereby enabling the spectator to view it through the second window. When the block appears in the second window, the initials on it are now those of the performer. The block is removed from the tube and given to the spectator to examine. The spectator's initials have disappeared, only the performer's remain. Includes instructions. Initial on the block is WK. Very good condition.