Description: 100% brand new and high quality. Material: Acrylic, Steel Balls Color: White Newton's cradle, named after Isaac Newton, is a device that demonstrates conservation of momentum and energy via a series of swinging balls. When one on the end is lifted and released, the resulting force travels through the line and pushes the last one upward; or pushes one side, all balls will swing together in a line. The device is also known as an executive ball clicker, Newton's balls, or Newton's pendulum. Great for home ornament, study or office desk table decor accessories, etc. Also good for birthday gift and kids toy Size Chart: L x W x H: Approx 16 x 8.5 x 11.5cm/6.30 x 3.35 x 4.53inch Package Includes: 1 Set Newtons Cradle Balance Balls Toy Note: Due to the manual measurement, please allow 1-5mm differences in size