Ready, set, go. Get familiar with the concept of motion, elasticity and momentum faster than your car can race past the finish line. Smartivity's STEM wheels mods off-roader car building block kit, educational, DIY, learning, construction activity toy gift take adrenaline rush to the next level. Build your own car, load it into the launcher and watch it go zoom. Challenge your friends for a race and compete for the title of the master racer.