The Track Builder Unlimited Power Boost Box combines classic track building play and a digitally connected racing system that revs competition and experimentation Designed to be compatible with other sets and the Hot Wheels id system (sold separately) for enhanced versatility and epic Hot Wheels action. Challenge kids ages 6 to 10 years old with exciting racing and stunting opportunities that they customize themselves with Track Builder Unlimited. Includes an innovative dual booster in the lid and 20 plus feet of track and parts for 4 plus racing and stunt configurations compatible with the Hot Wheels Race Portal (sold separately). Kids can create any race or stunt they can imagine with Track Builder Unlimited. Ready, Set, BUILD.