Features: Excellent educational science-gadget: Not only demonstrates a pendulum, but also shows the laws of conservation of momentums and energy. Science toy: When feeling tired of studying and working, you can stir balls to hear the clinking sound to eases. Excellent educational & science-gadget, own your very own piece of scientific history and explore significant values of physics. Pull back one or more of the balance balls, release them and the same number of balls will swing up on the opposite side. Great for home ornament, study or office desk table decor accessories, etc. Also good for birthday present and kid toy. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual measurement Description: Material: Solid-Wood+Fishing Wire+Carbon Steel Ball+Metal Bracket Size:14 x 12 x 14.5cm / 5.51 x 4.72 x 5.71in Package List: 1X Z Type Pendulum Ball Note: 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.