These are RPM 30° Front Caster Blocks for the Traxxas Electric Stampede and Rustler. 
These blocks mount to the front A-arms and is what the steering knuckles attach to.

FEATURES:  Nylon construction, black in color
           Stamped right and left to insure correct installation

INCLUDES:  Two RPM 30° Front Caster Blocks

REQUIRES:  Assembly between A-arms and steering knuckles