Features 1.Friction and damping effects are also observed. 2.Excellent educational science gadget. Not only demonstrates a pendulum, but also shows the laws of conservation of momentum and energy. 3.Science toy. When feeling tired of studying and working, you can stir balls to hear the clinking sound to ease. 4.Excellent educational & science gadget, own your very own piece of scientific history and explore significant values of physics. 5.Pull back one or more of the balance balls, release them and the same number of balls will swing up on the opposite side. Specification Description: This motion toy is made of stainless steel material, anti-rusty, safe and smooth to touch. Great for home ornament, study or office desk table decor accessories, etc. Also good for birthday gift and kids toy. Features: Made of stainless steel material, anti-rusty, safe and smooth to touch. Put on the desk steadily, do not occupy the space. As an educational toy to improve your children's study about perpetual motions. When you put the small people on the plastic base and poke it, it will swing on both sides for a while. Excellent educational & science gadget, own your very own piece of scientific history and explore significant values of physics. Great for home ornament, study or office desk table decor accessories, etc. Also good for birthday gift and kids toy. Specification: Condition: 100% brand new Material: Stainless steel and Plastic Color: Sliver Size: 18 x 11 cm / 7.09 x 4.33 inch(appr.) Package Included: 1 Set Motion Toy Note: 1. Please allow 1-2 cm error due to manual measurement and make sure you do not mind before ordering. 2. Please understand that colors may exist chromatic aberration as the different placement of pictures. Package List