Features: Brand new and high quality. Not only demonstrates a pendulum, but also shows the Laws of Conservation of Momentum and Energy. Friction and damping effects are also observed. Often used as a toy to amuse people. Includes steel balls, plastic frames and base. Great gift for everyone. Size:18cm x 11cm x 14cm - 7.09inch x 4.33inch x 5.51inch. Package Included: 1 x Balance Balls Desk Toy