Toy category: educational toys & games targeted group: unisexmanufacturer recommended age: 6 years & aboveage: 6 years & abovebrand: othersize: 14*17 cmnewton cradle steel balance ball physics science pendulum desk fun toy giftnewton''s cradle is a timeless, classic desktop science toy that is the perfect blend of science and art. Lift one steel ball and allow to fall back at one end, the ball at the opposite end will swing out the same distance. Fascinating to watch. Also known as balance balls, newton's pendulum and newton's balls, this executive office toy demonstrates the law of conservation of momentum. Using newton's third law has never been this much fun. What happens when you swing two Or three Highlightsmaterial: solid steel ball, nylon plumb line, abs plastic frames and base. It is a best and useful gift for children to arouse his or her interest in physics. Not only demonstrates a pendulum, but also shows the laws of conservation of momentum and energy. Friction and damping effects are also observed. Pull up one ball and release, only one ball in the other side moves, pull up two, two balls will react, and so on. When you are sleepless, just move your eyes with the bump of the ball, then you may slowly, slowly falling asleep. Watching the bump of the ball is a special way to pass the dull hours. Suitable for the place such as office, desk table, computer table etc. Note: this is only a toy, not professional newtons cradle. Movement will last only a couple of seconds. Only to demonstrate transfer of energy, momentum and effects of dumping. Material: metal, abspackage contents: 1 x newton cradle steel balance ball physics science pendulum desk fun toy gift.