CNC Machined from high-grade aluminum, our rear hub carriers feature a set-screw over hinge-pin design that securely keeps the hub carriers on the hinge-pins. This also keep the wear to a minimum by making the hinge-pins rotate in the arms and not in the aluminum hub carriers while increasing the durability. Plus, it adds an awesome factory look to your Slash 4x4.  (Note: setscrew in rear hub to be used with ST3640RS and ST3640RBK lock-nut style rear outer hinge-pins only. Setscrew is not used with kit type hinge-pins)