The Hot Wheels® Track Builder System offers the ultimate track experience for boys by allowing them to design, create and customize their very own track challenge. Using a variety of stunts, track layout options and key track essentials that all work together within the Track builder system, or connect to existing sets, boys can be the master of their own track. The assortment features a variety of cool, complex and simple car-activated stunts like this innovative Stunt Barrel™ challenge! Drive your car in, watch it tumble down the hill inside the barrel, and drive off at the bottom! Features: The Hot Wheels® Track Builder System offers the ultimate race experience allowing boys to design, create and customize their very own track challenge Assortment features a variety of cool, complex and simple car-activated stunts like this innovative Stunt Barrel™ challenge! Drive your car in, watch it tumble down the hill inside the barrel and drive off at the bottom! Unique roll-down launcher! Combine with other Hot Wheels® sets to create more track options. (Sold separately)