Description:With solid steel ball design, the product has good drape.With Newton's cradle design, you can see how the law of conservation of energy works.Made of high quality metal and ABS material.It is durable and waterproof.There are 3 sizes you can choose from:Small, Medium, Large.It is suitable for physics science, children teaching, room decoration, etc.Item Name: Newton PendulumMaterial:Plastic,MetalSize:S: 9cmx8.5cmx7cm/3.54inx3.35inx2.76inM: 13.5cmx13.5cmx11.5cm/5.31inx5.31inx4.53inL: 18cmx18cmx15cm/7.09inx7.09inx5.91inNotes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 X Newton Pendulum