Giant Color Changing Ball to Square

The magician displays a red ball and places it into his left hand. Suddenly, the ball disappears and is found to have jumped into the performers right pants pocket. He places the coloured ball on top of his left closed fist and pushes down inside his hand with his index finger. He asks the spectators which hand contains the red ball and no matter what they answer, the spectators won`t be right-in the magician`s left hand is a large (3.5 inch) red square and in his right hand is a black ball! 

Comes complete with all the necessary sponges.