These are the ST Racing CNC Machined Aluminum Rear Hub Carriers for the Traxxas Slash 4x4 and Stampede 4x4 in high-quality gun metal anodized aluminum (1952GM). Along with the CNC machining from high-quality anodized aluminum, these rear hub carriers utilize a set screw rather than the usual hinge-pin design. This configuration increases durability while minimizing wear since the hinge-pins turn in the arms rather than in the hub carriers. And the gun metal anodized aluminum adds a professional look to your Slash or Stampede 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) FOR USE WITH: Slash 4x4 Stampede 4x4 Nitro Slash 1/10 Rally 4WD