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 appearance an eye-catching desktop decor. Fuel is anhydrous ethanol or 95% medical-alcohol. after filling the fuel, wait for the water to boil, then gently push the , it will start to rotate. Water needs to be added to the 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 kids' science project, Physical/mechanical learning, Demo props on the class, inspiring children's interest in science and physics learning. Note: 1. The fuel needs to use anhydrous ethanol or 95% medical-alcohol. 2. The needs water to produce steam to rotate. 3. The package does not contain alcohol. You are required to purchase by yourself. Please understand the inconvenience. Colour:Gold & Silver & Green Material:Metal Size:Model Size:12x9x13cm/4.7x3.5x5.1in(Assembled) Package Contents: 1 * Stirling Engine Model Kit(shipped in parts, not finished products, need to be assembled) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.