Classic desk accessory.
Illustrates Newton's Principle that "action and reaction are equal and opposite." When one of the 5 steel balls at either end are lifted and swung back, the ball at the other end will swing out the same distance as the one you lifted. This item is listed as "new-other" as it is a display piece but is undamaged and still has original packaging. Measures 5-1/2" wide x 5-1/2" deep x 5-3/4" tall. Feel free to ask any questions!