This Robinson Racing Products pinion gear features a 5mm bore and 12 teeth cut to the 1.0 module pitch, making it a direct fit for a wide range of 1:10 scale electric touring cars and sedans. The extra hard treatment gives the metal gear increased durability for demanding drivetrain use. It ships with a set screw for secure motor shaft mounting. Features: 12-tooth, 1.0 module pitch 5mm bore Extra hard metal construction Includes set screw 7/7/26 cs