Features: ★ Dual cylinder engine is full of power and the voltage can reach 12V. The flywheels will rotate rapidly, making the generator's Lamp bulb lighting. When the machine works, it will be very shocking and attracting eyeballs. ★ Selected high-quality metal materials, golden appearance, exquisite workmanship, high-precision coordination of various parts, stable and firm base, ★ Superior Performance: By operating the engine, children would observe and know the operational process and more intuitive understanding of the operating principle of Stirling engine, deepening interest in physics. ★ Great Educational Toy: classroom or laboratory experimental teaching aids, the best choice gift to students, teachers, children, friends and colleagues. ★ Easy to Operate: Fill the alcohol burner with your 95% alcohol (we recommend this fuel) and light it. Let the light burn the round ended cylinder for about 2 minutes, then give the wheel a gentle push. Specification: Model: s1 Material: Metal Voltage: >12V Size: 17 x 12.5 x 8cm/6.7 x 4.9 x 3.1in Weight: 193g/6.8oz Package Size: 23 x 16 x 13cm/9.1 x 6.3 x 5.1in Package Weight: 1270g/44.8oz Packing List: 1 x Stirling Engine Motor Kit