This Associated factory replacement steel pinion gear is designed for Mod 1 drivetrains with a 5mm motor shaft. The 16-tooth count is engraved on the gear for easy identification, and a set screw is included for securing the pinion to the shaft. Built for Associated 1:8 scale electric competition vehicles, it is a direct-fit replacement for maintaining proper gear mesh and drivetrain performance. Features: Steel construction for durability 16-tooth Mod 1 pitch 5mm shaft bore Includes set screw 7/7/26 cs