These are the Traxxas Hardened Steel Rear Driveshafts for the Traxxas 1/10 Scale Slash 4x4, Slash 2WD, Rally, and Stampede 4x4 vehicles.
Traxxas Steel Constant Velocity Shafts offer the ultimate in torque handling and
efficient power transfer. The outer U-joints are lubricated and sealed by a
rubber boot for maximum protection against the elements, and the U-joint pins
are held captive so you never have to worry about losing a pin. Gleaming
nickel-plated shafts and silicone boots add a custom look.