Traxxas 5585 2-Speed Gear Set, 27-T 2nd Gear and 17-T Input Gear Use Traxxas stock and hop-up replacement parts to get the most out of you Traxxas RTR vehicles This product is made from high quality materials and designed for lasting performance This is for use on RC vehicles such as the Traxxas Jato; consult your user's manual for exact parts listings