Our Modular Building System uses retained screws that won't fall out for quick and easy on-the-go customization. Just loosen the screws with the hex tool provided and swap out parts! Every piece is interchangeable across every Modarri car. Put yourself in the driver's seat. With Modarri PRO's real suspension and finger-steering mechanics, you can perform figure eights and tight turns without ever having to re-position your hand!