The Traxxas extreme Heavy Duty Front Outer Stub Axle assembly is a rugged, factory-replacement drivetrain component. 
It is engineered explicitly to withstand intense bashing and high-power setups in Traxxas 4X4 1/10 scale vehicles.
Comes fully assembled with the internal-splined heavy-duty outer half shaft pressed onto the steel stub axle.
To form a complete functional driveshaft, this assembly requires the 6828A differential output assembly on the inner side. 
Note that it is not compatible with standard, non-HD driveshaft setups due to beefier sizing.