This Stirling engine model can clearly explain the principle of aerodynamics. Features: A Stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas (the working fluid) at different temperatures such that there is a net conversion of heat energy to mechanical work. Teaching will be more intuitive and more interesting. Student can understand it quicker and better. The assembly process is quick and easily. Specifications: Model: LL-002 Material: Galvanized Iron Sheet & Glass Speed: Up to 200rpm Engine Size: 16.2 * 8.8 * 8.3cm / 6.4 * 3.5 * 3.3 Engine Weight: 308g / 10.8oz Package Size: 17.5 * 9.2 * 11cm / 6.9 * 3.6 * 4.3 Package Weight: 464g / 16.4oz Package List: 1 * Stirling Engine Self-assembly Kit 1 * Lamp (Without liquid) 2 * Spare Tube 1 * User Manual(English/Chinese) Note: 1. Glass should not be exposed to water after being heated or otherwise it will split. 2. If the is spill please use cloth to put out the fire. 3. Children under 12-year-old should be accompanied by adult when using this product.