The 7cm Plasma Ball gives you a lightning show in your own room. The glass bulb is filled with negative ionised gas through which the current appears to travel like lightning. When you touch the lightning globe, the electricity is attracted to your finger in a single thick strand as it tries to get to the ground. The lightning ball has 2 different modes - normal (as described above) or sounds activated! Plasma Balls are great geeky gifts and an awesome desktop gadget. Perhaps give this gizmo as a thank you present to your science teacher or use it to light up your bedroom. It's positively electrifying!