This is the Robinson Racing Xtra Hard Steel 16-Tooth Pinion Gear with a 5mm shaft hole. This is perfect for use on the Traxxas Revo and E-Maxx when running electric motors with a 5mm shaft.
Features:
Extra hardened steel construction for durability
Precision made
For use in extreme conditions
Includes: One 16 tooth pinion gear, One 4x4mm set screw