1. Exquisite Workmanship: Black, well-finished wooden casing, quiet and generous, metal frame, sturdy and durable, each metal ball can swing for a long time. 2. Swing Time: The heavier the weight of the ball, the more friction between the balls can be reduced, the longer the swing time, the total weight of the balls is about 100g, which can swing for a long time. 3. Easy Installation: Simply place the frame into the hole in the wooden box, and the installation is complete. The dimension of the finished product is approximately 9*7.5*9cm (L x W x H). 4. Multi-functional Item: Due to their various fun playing styles, all children are very easily captivated by the Newton's cradle, a nice gift for them; and as a desk decoration, it can help you release a lot of pressure when you watch the swinging balls. 5. No Tangled Strings: Unlike competitors, everything is neatly packed and secured to ensure the strings don't tangle upon arrival.