Vuelo moneda caja mágica

Magician show two cylindrical metal caps and a metal ring and offer them to a person in the crowd for examination (no force). Both the caps will be seen to be completely empty. And then, five coins mysteriously appear under one of the metal caps. As soon as they appear,they suddenly vanish only to reappear under the second metal cap previously shown to be empty! The coins continue to jump from one cap to the other,it can even penetrate through the solid metal from one container into the other. For the big finisher, all of the coins vanish without trace !