Simply turn the handle, the electricity generated makes the bulb bright. The you turn the handle, the more power you generate. Amazing handheld electricity generator! Create power without batteries! Great for classroom physics teaching demonstrations. Made with a clear plastic casing, students can clearly see the motor, gears and wiring. This science kit is perfect for demonstrating the energy transformed from mechanical to electrical. This grip handle generator allows connection to electrical circuits. Screw out the miniature light bulb, can be used with almost any experiment requiring up to 6.3 volts DC.