Features: It expresses a kind of pioneering spirit and strike lucky. It’s the best gift for customers, leaders, friends, husband or children which could bring them very surprise.  With the help of the flywheels, then a net conversion of heat energy to mechanical work. Mechanical work through small generators produce electricity to power a light bulb.  Can be used for teaching purpose.     What is the Stirling Engine?  A Stirling engine is a heat engine that operates by cyclic compression and expansion of air or other gas, the working fluid, at different temperature levels such that there is a net conversion of heat energy to mechanical work.The engine is like a steam engine in that all of the engine's heat flows in and out through the engine wall.     How it works?  This is traditionally known as an external combustion engine in contrast to an internal combustion engine where the heat input is by combustion of a fuel within the body of the working fluid. Unlike the steam engine's use of water in both its liquid and gaseous phases as the working fluid, the Stirling engine encloses a fixed quantity of permanently gaseous fluid such as air or helium. As in all heat engines, the general cycle consists of compressing cool gas, heating the gas, expanding the hot gas, and finally cooling the gas before repeating the cycle.    Specification:  Item Name:Metal Power Generation Stirling Engine;  Material: Zinc alloy&Aluminum alloy&Stainless steel; Dimension: 180*90*85mm; Weight: 420g;    Package Included:  1 x Metal Power Generation Stirling Engine(not included alcohol)