1. Material: wood 2. Applicable age: over 8 years old 3. Product principle: drive the generator to rotate through the hand-cranked large disc to realize the output of electric energy to light the bulb 4. Product features: interesting scientific and educational toys, exercise hands-on ability 5. Extended hand crank, easy and labor-saving rotation 6. Red wheel fixed, balance device 7. Wire perforation design, standard and neat 8. Product size: 16 x 12.5 x 8.5 cm 9. Note: Self-assembly is required, and instructions are provided!