Description: Balancing toys were popular in the 19th century. Dating back to ancient China and India, where they were most often carved from soft wood, the western balancing toys were traditionally made from tin or metal. Illustrations of balancing toys can be found in educational literature from the 18th century. The physics governing the movement of such toys intrigued and amazed people. Balance toys came in various forms, and our particular shape is traditionally. This classic desktop toy provides you many benefits and entertainments, is suitable for various locations such as house or office, and is an intriguing device that not only demonstrates pendulum motion, but also helps to show the laws of Conservation of Momentum and Energy. Whether you are studying physics knowledge, working on complex analysis, or looking for a delicate gift, this toy is definitely what you really want. Features: Total height: 140mm / 5.51 in Total length: 235mm / 9.25in Base diameter:50mm / 1.97in Net weight: 158 g / 0.35lb Material: silver steel. Packing: in box. Package Content: 1toys 1base Attention: It is not an item that never stops working. It moves and swing after you push, and finally it will stop due to the resistance of the air and friction if you know more about the law of energy conservation, you will not ask why.