Features: 1. Thermal energy is converted into mechanical motor energy of the engine, which can be operated by hand more intuitive understanding of the principles of movement and deepen your interest in physics. 2. Easy to assemble, valuable for collecting, can be used as school laboratory supplies. 3. Widely used in childrens science projects, physical/mechanical learning, classroom teacher demonstration props. 4. Scientific design of the whole structure to ensure system integrity and stability 5. Made of high quality materials, safe and eco-friendly, sturdy and durable. Specifications: Condition: 100% Brand New Item Type: Sterling Engine Model Material: Iron Function: Thermal energy is transformed into a mechanical sense of motion. By manually manipulating the energy of the engine, you can understand the principle of operation more intuitively Package list: engine model x 1, cotton cloth x 1, blue cover x 1, jar x 1.