Magic Trick Box With Face Dice

This item called Measure The Faces, a hot sale product and really popular in the world.
The magician show us a round box and one transparent dice. There are three designs on dice: smile, weep, angry, then let audience choose any one, must let the design upwards, put it in the box, close the cover, the magician can know the design under unware condition, and the action can repeat.
Magic Trick Box With Face Dice