Description: The fan are fixed in the transparent air outlet pipe. Demonstrations can be viewed from multiple perspectives. the bottom plate and light it to let candle, and fasten the box. Place outlet with fan on the air outlet. smoke source air inlet. At , it can be seen that flows from the air inlet through the combustion chamber to the air outlet pipe, forming wind and making the fan rotate. Function:This visual aid for teaching physics. Feature:The emergence of wind shows the box for the natural class to the formation to explain wind. Link:Intuitive image with the reasons wind formation. Advantage:Make to help the teachers, the principles to .Improvement of scientific interest of Size Chart: 6.3cmx13.1cm/2.48inchx5.16inch Package Includes: 1 Teaching Instrument. (6 Pack) Note: 1.This is not infant toy, please take away from children to avoid eating. 2.Please allow slightly errors due to manual measurement and different monitors.