Newton's Cradle Fun Steel Balance Ball Physics Science Desk Toy Accessory Gift 100% 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. Original box: Yes Color: Black & Silver Item size: 90*76*92mm Packaging size: 95*82*32mm Net weight: 100g Package weight: 110g 1 x Newton's Cradle Balance Balls Desk Toy