Description: Steel balls, ABS plastic base and nylon wires, are all seperatedly by foam boards during our packing, no worries about items getting tangled! A fantastically relaxing object to have ticking and clicking away at your fingers as you are working, play or rest Sit back and watch the soothing motion of the steel balls swinging back and forth, listen to the gentle click as each balls tap each other No matter how stressed out you are, Newton Balls will have you relaxed in minutes Creative ornaments for home office desk table top decoration, a classic fun gadget desk toy for everyone! Specification: Material: ABS plastic base and steel balls Ball Diameter: 16mm / (all three Newton's Cradle using the balls of same size) Large Size(L*W*H): approx. 18 x 15 x 18 cm / 7.1 x 5.9 x 7.1 inches Medium Size(L*W*H): approx. 13.5 x 11 x 13.5 cm / 5.3 x 4.3 x 5.3 inches Small Size(L*W*H): approx. 9 x 7.5 x 9 cm / 3.5 x 3.0 x 3.5 inches Color: as shown in the pictures Newton's cradle, named after Isaac Newton, is a device that demonstrates conservation of momentum and energy via a series of swinging spheres. When one on the end is lifted and released, the resulting force travels through the line and pushes the last one upward. The device is also known as an executive ball clicker, Newton's balls, or Newton's pendulum. Package Includes: 1 Piece Newton's Cradle Note: Please understand that plated rod may have a little plating fading due to hand crafting before you bid. Due to manual measurement, there may be 1-2mm error in size.