Overview Extra hard high carbon brushless motor pinions are built to last with hi-performance GEN3 steel slipper units. Pinion is precision machined and stamped with the number of teeth. One 4mm set screw included. 2mm allen wrench (not included) fits the 4mm set screw. Can be run on cars using a 5mm motor shaft. 5mm to 1/8 inch Reducer Sleeve required for 1/8 inch shaft motors. Note: 32 pitch and .8 module gears can be used together with no adverse affects such as increased noise or increased wear. The difference is that .8 module gears have a slightly larger outside diameter per tooth, roughly .00027 of an inch.