[Automatic rotating]:The glass Radiometer will rotate automatically under the sunlight or strong irradiation [Table decoration]:Rotating Vanes Desk Toy can be used for decoration in offices,living rooms,bedrooms,classrooms,study rooms,parties,etc [Educational]:Glass Windmill with an internal vacuum.It can rotate by itself through light,and can also rotate in the opposite direction through cold wind [Principle]:When the light black fan absorbs heat energy,white fan releases heat energy,it can promote the four fans rotation [Material]:Solar Power Crookes is made of glass,great for Physics teaching tool, Manufacturer: Zanthicia