The Newton's Cradle teaches principles of physics in a fun, hands-on way. Pull back one of the polished steel balls on one end and watch it swing into the next, transferring its energy to the ball at the far end of the line and causing a chain reaction. You can release multiple balls at once and observe the different effects. A great way for people of all ages to learn and observe physics in action. The small device fits perfectly on a desktop or coffee table. Recommended for ages 5 years and up.