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. The electric engine generate enough power and light up the mini lamp after it reach a certain speed. Inspires students' curiosity, make teaching more intuitive and interesting. With fancy appearance and compact body, is undoubtedly the best decor for your home or office. Hot Air Stirling Engine Size: 145 * 90 * 84mm.