Four glasses of different sizes are shown, from large to very small. The large glass is full of milk. The performer pours all of the milk into the next smallest glass and it all fits perfectly. This is repeated with the next smallest glass and again all the milk fits into the smaller glass. This is repeated until all the milk from the largest glass fits perfectly into the tiny glass! An amazing trick! Can be performed in reverse, where the milk in the small glass fills the largest glass!