The Energy Ball is all you need to safely introduce students to electric energy. This is a fun way to demonstrate open and closed series circuits without any danger of electric shocks! When the ball is 'turned on' from inside the 1.5-inch ball, a red light flashes and a buzzer buzzes. Activating the ball is the fun part - just touch the metal strips with your two index fingers. Your body forms the conducting material that bridges the gap between the two metal strips and closes the circuit!