Sunnytech Hot Air Flame Licker Stirling Engine Motor Model Education Toy Electricity TZ (TZ02G) Stirlingtechonline is exclusive distributor and the owner of the brand "SunnyTech"----Please be sure you receive an authentic SunnyTech stirling with SunnyTech logo and only sold by Stirlingtechonline to ensure 1-year 100% Satisfaction Guarantee. it's a already finish assebmbled toy.you will receive a finised product exactly as the picture,just take it out from the box, and play.No any drilling or soldiering required. 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. 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 Candle's light is not workable for this toy, please pay attention.