A great metamorphosis effect done with two beautifully made flat black dice. One has four spots on top and three spots underneath. The other has five spots on top and two spots underneath. After pointing out that the top and bottom of each die add up to seven, you quickly change the first die from 4 and 3 to 5 and 2! Quicker than a wink the dice change places again! And again!
No shells, no magnets, no sliding parts of any kind! Just pure magic!
And here is the video demo from the manufacturer: