The back and ahead motion is a soothing experience, you'll enjoy day after day, learn about the conservation of motion and energy. If you feel tired of studying and working, you can stir balls to hear the clinking sound to ease. The steel ball can swing back and ahead, which is a very interesting decompression toy. Using high?grade metal and steel materials, it is durable and long service life. The length of base is 18cm, the width of base is 11cm, the height of balance ball is 11cm. It is great for home ornament, study or office desk table decor accessories, etc. Item Name: Newtons Cradle Material:Metal,Steel Size Details: Size: 18.5cm x 18cm x 11cm/7.28" x 7.09" x 4.33" (Approx.) Notes: You will find more amazing products if you visit our store. Due to differences in lighting and screen settings, the color of the project may be slightly different from the picture. Due to different manual measurements,allow for slight size differences. Package Includes: 1 X Newtons Cradle