[Principle]: Sun light vanes, when the sun shines, the black vane absorbs heat , and the white vane releases heat , that drives the vanes to rotate [Premium Material]: The solar Crookes radiometer windmill is made of premium high glass, sturdy, not easy to break and crack, and ensures a long time to use [Desktop Ornament]: The solar power Crookes radiometer is a addition to your home decoration, suitable for decorating the desk, table, shelf, cabinet, entrance, fireplace, , bedroom, living room, etc [Educational Science Toy]: The solar power Crookes radiometer is a physics teaching toy, under sunlight or strong irradiation, the vanes inside automatically rotate [ Gift]: The Crookes radiometer is a gift choice for kids, family and friends on Christmas, birthdays, parties, festivals, housewarmings, etc, Weight: 0.43871990138 pounds, Manufacturer: Tuidzljd