Features:DIY unassembled Stirling model kit, enhance hands-on ability, experience the fun of assembly. The size after assembly is 12x9x13cm/4.7x3.5x5.1in.Made of high quality metal, enabling the model sturdy and durable. Metallic texture and unique flying saucer appearance make it an eye-catching desktop decor.Fuel is anhydrous ethanol or 95% medical alcohol. Ignite after filling the fuel, wait for the water to boil, then gently push the flying saucer, it will start to rotate.Water needs to be added to the flying saucer to produce steam to make the it rotate, very easy to operate. Mute design, give you a comfortable environment and don't disturb others.A fantastic gift for kids' science project, Physical/mechanical learning, teachers Demo props on the class, inspiring children's interest in science and physics learning.