This kit provides a smashing lesson on pendulums and the effects of energy and motion. Assemble the Wrecking Ball using KEVA planks, wood glue and the architecturally-inspired blueprint instructions. Once built, turn the winding drum to adjust the hoist rope for maximum impact. The kit comes with everything you need and includes 20 wooden target planks. The completed Wrecking Ball stands nearly 3 feet tall, while the removable boom arm allows for easy storage.