Note: The color of the product we ship is the color in the first picture, and the specification and quantity are shipped according to the quantity and specification described in the title. If you need to change the color or style, you need to contact us within 12 hours after placing the order. Our product description: Mini Hot Air Sterling Engine Model Steam Powered Electricity Aerodynamics Science EducationSpecifications: Product material:metal,glass Color:Silver Size:165x87x95mm Product Features: 1. Can effectively cultivate children's interest in learning 2. Can also be used for classroom teaching and easy to understand. Note: - When there is too much steam , the engine will stop working. Please set aside the inside and outside needle to reduce friction. - Do not rotate the nut tightly, otherwise the glass will be broken. If the piston is cracked, you can be bond with glue. - The alcohol lamp wick could not touch the glass and get to the hole so tightly. - When pulling the piston, please do not force the front end, it is easy to break. Package include: 1 x Stirling Engine 1 x Alcohol Burner 2 x Spare Heating Tube Note: Because the model and display effect of the monitor may be different, there may be slight differences in color, and the size is manually measured, there may be an error of 1-2cm, please understand.