This science kit is perfect for demonstrating the energy transformed from mechanical to electrical. 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. Simply turn the handle, the electricity generated makes the bulb bright. The faster you turn the handle, the more power you generate. This grip style 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. Colour: transparent + green Material: plastic Package Contents: 1 x Hand Crank Generator Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.