Pendulums Are Classic Desk toys They Are Also Known As A Ball Pendulum. of Cradle. Cradle or Perptual Mobile. Height: 180Mm - Weight: Over 0.8Kg - Fashionable - Modern Design - Metal Gift. Newton Cradle Is Classic and Timeless Desktop Science. Which Is The Perfect Blend of Science and Art. Suitable For Kaise Children to Experience The Fun of Mechanics While Playing with This Fun Device. If One of The Outer Stainless Steel Balls In The Metal Frame Is Knocked Against The Others. The Central Balls Apparently Remain Stationary. Only The Ball At The Other End of The Chain Collides with The Ball. with 2 Striking Balls. The Central Ball Remains In Place. But The Two Opposites Are Balanced. Versatile. You Can Use It Like A Physical Device. An office tool. A Stress Killer and As A Great Gift and Desk Decoration. A Nice Gift For Kaise A Friend.