Two bottles and two cylinders are shown. One of each is handed over to a spectator as the performer holds on to the other. The performer then instructs the spectator to follow his moves. The cylinder is placed over the bottle, held between the two hands and turned over a number of times. When the performer lifts his cylinder, his bottle is always right side up and spectator finds his upside down!
This can be repeated several times much to the delight of the audience.