Balance Balls ( Newton's Cradle) are used to demonstrate one of Newton's physics laws - you know - the one about equal and opposite forces. Thes swing balls are about 4.5 inches tall and roughly 4 inches square. The chrome supports and base are plastic and the balls are metal. Comes in a gift box. This contraption is hard to resist and in our store, these balls were swinging all day long as every customer just had to try them out! |