Sunnytech Hot Air Stirling Engine Education Toy Electricity Power Model TC (TC006) 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. See play video : 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. It is a amazing and fantastic product at this price,it can be a great gift to your families or friends. It also can be used for teaching purpose. Many of our customers comes from school,colleague,etc Weight: 400g / 14.11 oz Size: 116mm X 60mm X 62mm / 4.56in X 2.36 in X 2.36 in