Tamiya Big Truck Options Spare Parts Hub Nuts for Double Tires Black 2 Pieces RC Parts 56557 & No.57 TROP.57

Use this in place of the 4mm flange nut that comes standard with the kit. Secure the wheel with the inner nut, then screw the outer cap onto the inner nut. The aluminum outer cap, which realistically replicates the shape of the hub nut on an actual vehicle, enhances the realism of the finished product.