[Exquisite Workmanship] Well-finished black wooden case, quiet and generous, nylon strings and stainless steel frame, strong and durable, 46g each metal ball which can ensure a long swing time [60 Seconds Swing Time] The heavier the ball weight, the friction between the balls can be reduced, the longer the swing time, the total weight of the balls is about 260g which can swing up to 60 seconds [Simple Installation] Just put the frame into the hole of the wooden case, then will finish the installation, the finished production dimension is about 18 * 12 * 18 cm (L * W * H) [Multipurpose Items] Because of its funny way of playing, every child is very easy to be attracted by the newton's cradle, a nice gift for them; and as an office desk decoration, it can help you release a lot of pressure when seeing the swing ball [No mess with tangled strings] Unlike the competition, everything is carefully packaged and secured in place to ensure the strings will be tangled upon arrival