This 2-speed kit comes with a full set of heat treated hardened steel machined gears, plus an additional optional high speed gear, full set of cartridge bearings, two different servo mounting options, servo saver system and all necessary hardware to complete the installation. First gear ends up a being a 2:1 reduction intended for slow technical crawls while the Hi Gear is based off the stock 1.08:1 ratio and Hi Gear Option increases top speed with a 0.93:1 ratio. Shifting between the gears can be done on the fly while driving from the convenience of your radio.