Specially-designed 2WD/4WD rear wheels with 12mm internal hex. The center countersunk area had been redesigned to position the wheel nut deeper. Precision fit, perfect for high-competition racing. Produced from flexible, durable product to withstand impacts. The medial side of wheel is aerodynamic for optimum performance. Special options that come with the wheel are visible through the inside: reinforcement ribs to help make the wheels as stable as you are able to and eradicate deformation.