Newton's Cradle Approximately5 1/2" tall4 1/4" wideBalance Balls are a classic desk toy. Also known as Newton’s Cradle, the clacking of the steel balls will keep you entertained throughout the day. Pull back one or more of the balls, release them and the same number of balls will swing up on the opposite side. This set of balance balls is fun for the office and makes a great desktop gift. 1. The apparatus. The apparatus usually consists of an odd number of identical steel balls each suspended by a bifilar suspension from a sturdy frame. This is a representation of what the item does, the following picture is not the actual item (actual item pictured at top and bottom of this page) The balls are carefully aligned along a horizontal line, just touching. When the ball on one end is pulled aside and allowed to swing as a pendulum, it hits the next ball. But the outcome is fascinating, the one ball on the far end is knocked away from the others with the same speed as the first ball had initially and all of the other balls remain nearly at rest. If you pull back two balls and let them strike the others, two balls are knocked from the other end, and all the other balls remain nearly at rest. Please Check out All out Cool Items at our eCRATER Store"Smunks Shop" By clicking the Banner below. Shipping InformationPlease see Below for our Shipping pricesWe used to write them out in the Description but with fluctuating rates all the time we have been forced to stop. Prices are listed below in eCRATER's form for both Single and Multiple Items, If you do not understand or have any questions feel free to ask! We Do ship outside of the US But, If you are outside the US you must contact me for a shipping quote prior to purchase, If you do not contact us for a quote you are bound to pay whatever price we must chargeNote, We Do Combine shipping and this is how it works:You are charged the Highest shipping price out of the shipping prices for the first item and then the additional Item Rate for every other item. If you are unsure just wait and you will receive an invoicePowered by eCRATER . List your items fast and easy and manage your active items.