When you put the radiometer within the sun, the vanes will maintain spinning. Put it in or the living room is very beautiful. It is a gift, ship it to our peers or kinfolk will love it! It is fabricated from glass,so it is fragile. It is suitable for children over 14 years of age. Colour: blue Material: glass Size: 14x7 Package Contents: 1 * radiometer Only the above package content, different merchandise shouldn't included. Note: Light and assorted reveals could cause the colour of the object within the photo a piece various from the genuine thing. The measurement allowed error is +/- 1-3cm.