Package: sunnytech® package and sunnytech LOGO stickered Sunnytech® Hot Air Vertical Stirling Engine Motor Model Educational Toy Electricity SZ001 （White） This is a Mini hot stirling engine, Its small size.You may receive and feel its small, so please pay highly attention about the size before you click "BUY IT NOW" Features: Single FLYWHEEL HOT AIR STIRLING ENGINE MODEL:SZ001 （White） Speed:1300 to 1500 RPM Size: 54mm bottom diameter, 135mm height Material: Steel,copper and Aluminium, Weight:300g 10.58 oz. IMPORTANT: 1.Please adopt 95% to highgrade alcohol to be the fuel to make sure the air tank can get more temperature, and drive the stirling engine. 2.The temperature of Candles light is not workable for this toy, please pay attention. 3. Usually it will last for about 3 minutes, and need cooling to restart. This is a vertical structure, the temperature of fire spread to the piston and reduce the temperature difference. If you want it last for longer, take a damp cloth to cover the cylinder body to take away the cylinder heat. No oil lubrication. packing list: 1 stirling engine 1 alcohol lamp The stirling is already assembled, you doesnt need to to do anything assemble work. 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 engines heat flows in and out through the engine wall.