Feature: 1. Metal bracket and metal piston are firm, and the whole is finely polished, which is very metallic and modern technology. 2. The product itself has been assembled, has collection value, and can be used as an ornament. 3. Thermal energy is converted into mechanical energy of engine, and intuitively grasp its working principle and deepen your interest in physics. 4. Meticulous polishing, bright color, it is not easy to rust and discolor, and the slot to hold lamp, which is safe and reliable. 5. By operating engine, children observe and understand the operation process, intuitively understand working principle of Stirling engine. 6. The model kit has a wide range of applications, suitable for scientific projects and physics/mechanical learning. 7. It can also be used as a classroom demonstration prop for teachers to facilitate teaching progress. Specification: Item Type: Stirling Engine Material: Zinc Alloy + Sheet Size: Approx. 16x7.9x8cm / 6.3x3.1x3.1in Function: The heat energy is converted into mechanical energy of the engine, which causes the light bulb to brighten, and hands-on operation makes it more intuitive to grasp its working principle . Package List: 1 x Stirling Engine1 x Lamp Bulb1 x Ethanol Lamp1 x Ethanol Pad2 x Elastic String (1Pcs installed on product)1 x Light Emitting Diode1 x Magnet Note: 1.Please allow 0‑1 inch error due to manual measurement. Thanks for your understanding.2.Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.