Gear differential precision internal gears made from new graphite composite mixture. Includes 2 bevel gears and 4 satellite gears. Molded from the all-new special lightweight and extra-strong graphite material which gives the gears an optimum balance of hardness, toughness, and flexibility to provide long life, minimal wear, and minimizing breakage or teeth stripping. The graphite gears are lighter which results in increased drivetrain efficiency. A âśmust haveâť for professional racers. Fits T4.