This mini stirling engine is an excellent educational toy that teaches kids & students the principles of physics. Made of zinc alloy & glass, it offers superior performance with low noise, low pollution & low operating cost. With added non-skid pads for safety, it runs quietly & stably for long periods of time. The simple operation involves adding 95% alcohol to the burner & igniting it. The transparent glass tube & lamp allow for direct observation of the piston, making it a perfect gift for students, teachers, children, friends & colleagues. Features: 1. Working Principle: The stirling engine is a heat engine, and its working principle is to cyclically compress and expand air or other gases at different temperatures so that the heat energy is converted into mechanical work. 2. Superior Performances: The model runs quietly and stably when it rotates, and can rotate for a long time. Low noise, low pollution, low operating cost. 3. Simple Operation: Add your 95% alcohols (we recommend this fuel) to the alcohols burner and ignite. Let the light burn the bob cylinder for about 30 seconds, then give the wheel a little push, and it will work like magics. 4. Excellent Workmanship: The stirling engine is made of zinc alloy and glass, which is exquisite and beautiful. There are non-skid pads on the bottom of the model, which is safe to use. The overall shape is exquisite, combining texture and beauty. 5. Amazing Educational Toy: Transparent glass tube and glass alcohols lamp, convenient for direct observation of the piston. It is the best choice as a special gift for students, teachers, children, friends, and colleagues. Specification: Material: Metal Product Color: Silver Package Size: 17.2 x 9.2 x 11cm Package Weight: 460g Package Included: 1 x Stirling Engine Motor Model