Power up Hot Wheels track builds with this awesome stackable booster kit! These versatile boosters connect to each other and to the two included intersections. These iconic Track Builder Unlimited stunt pieces are an incredible addition for building and rebuilding bigger and better stunt sets. Unleash their imagination with 5+ configurations! The Hot Wheels Track Builder Ultra Boost Motorized set is designed to be compatible with other sets (sold separately) for enhanced versatility and Hot Wheels action. Kids can choose their build, track performance and nail the win!