Specially-designed 2WD/4WD back wheels with 12mm interior hex. The center countersunk area had been redesigned to position the wheel nut much deeper. Precision fit, ideal for high-competition racing. Made from versatile, durable material to withstand effects. Along side it associated with wheel is aerodynamic for optimum performance. Unique options that come with the wheel are visible through the inside: reinforcement ribs to help make the wheels as stable as possible and eliminate deformation.