1. [Exquisite workmanship] Well-finished black wood case, calm and generous, nylon strings and stainless steel frame, tough and durable, metal which can ensure a long swing time^2. [60 Seconds Swing Time] The heavier the weight of the ball, the more friction between balls can be reduced, the longer the swing time, the total weight of the balls.^3. [Simple installation] Just put the frame into the hole of the wooden crate, then will finish the installation, the dimension of the finished production is about 18 * 12 * 18cm (L * W * H)^4. [Versatile Items] Due to its fun way of playing, every child is very easy to be attracted to the newton cradle, a nice gift for them; and as office desk decoration, it can help you release a lot of pressure when see the swing ball^5. [No mess with tangled ropes] Unlike the competition, everything is neatly packaged and secured in place to ensure the ropes will get tangled on arrival^