CERROPINewtons Cradle Pendulum with 7 Balls, Classic Swing Newton Balance Ball, 30+ Sec Swingtime, Science Physics Gadget, Desk Toys & Office Gadgets for Desk Decorations

You probably know how these work and it does exactly what you expect. It's a nice solid weight and the balls are heavy, so they transmit the force from one to another well. One thing that sets it apart is the version I bought features 7 balls, rather than the 5 they typically have. Shows the motion transfer well, and you can do things like swing 2 or 3 balls and see the reaction. Fun to play with!

I love things like this on my desk! I like to tinker while doing work. The movement and sound make it a peaceful environment to help my focus. I have bought others in the past that were crappy made out of plastic. This is well made with weight to it. I am very pleased with my purchase.

doesn't swing too long unfortunately but good fun

Quality product, good price. Fun way to demonstrate cause and effect.

Bought two of these. One for myself for my desk and one as a gift. Very sturdy cradle with significant above average motion times. I read some reviews that inferior cradles last ~25-30 seconds. These last ~37-45 secs. Also comes with an extra ball and wire. Very pleased with this purchase.

String snapped off of one side of one of the balls and cannot get it fixed. Son loved it until that happened.

Works and looks great. Looks as it does in the picture.

Would seem the balance or weight or something is off on this unit. The balls will swing like expected but they do not sit tight together therefore it will only run for about 30seconds and then peters out. Really disappointing for the cost.