This is an optional pair of Traxxas Steel Rear Driveshafts.
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 black silicone boots add a custom look.