Radiometer run by the sun

Product Description: Radiometer

From the Manufacturer: It's the spinner powered by the sun! The Radiometer has vanes that are alternately dark and light in color. When light strikes the diamond wings, it transfers heat to each one, but not to the same degree. The lighter vane reflects the rays and the darker vane absorbs the rays. The stronger the light, the more energy there is to heat up the darker side, causing the wings to spin faster. This product is suitable for ages 8 and above.