Due to the solid base and fine workmanship, the pendulum balls can be kept smooth operation. The pendulum balls demonstrates the principles of Conservation of Energy, which helps you to explore the mysteries of the natural science with your child together. Made of Metal and ABS plastic materials, which is wear-resistant and durable to use. The length of the product is 13cm, the width is 10cm, and the height is 7.5cm. This Newton's cradle is a perfect decoration for desks and tables, whether at the office, classroom or at home. Item Name: Newtons Pendulum Balls Material:Metal,ABS Color: Black Purple Orange Size:13cmx10cmx7.5cm/5.12inx3.94inx2.95in 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 Pendulum Balls