DescriptionEXCELLENT DESIGN Toy Newton's Balance Balls are an excellent educational tool. Shows not only a pendulum, but also the laws of conservation of momentum and energy. .SCIENTIFIC TOY When you are tired of studying and working, you can stir balls to hear the clink. .MULTIPLE FUNCTION Scientific Balance Balls are an excellent educational and scientific gadget, possessing their own piece of scientific history and exploring important values in physics. As an educational toy to improve your children's learning about perpetual motion. .USE WIDE decor balls pull back one or more of the balance balls, release them and the same number of balls swing up on the opposite side. Balance balls are widely used, ornaments can be used to decorate the family, and can also be used as children's toys.