Gear, 21-T pinion (32-p) (machined steel)/ set screw. Traxxas offers these precision machined 32-pitch gears to allow a variety of gearing options. Larger gears will increase the speed of the vehicle, while smaller gears will increase the torque. The machined-steel pinions include set screws and the larger gears are machined to remove unnecessary weight. Use Traxxas stock and hop-up replacement parts to get the most out of your Traxxas RTR vehicles. This product is made from high quality materials and designed for long-lasting performance. This is replacement hardware for use on Traxxas vehicles; consult your user's manual for exact parts listings.