Gear differential precision inside gears created from completely new graphite composite combination. Includes 2 bevel gears and 4 satellite gears. Molded from all-new special lightweight and extra-strong graphite material provides the gears an optimum stability of hardness, toughness, and freedom to produce endurance, minimal wear, and minimizing breakage or teeth stripping. The graphite gears are lighter which leads to increased drivetrain effectiveness. A must have for expert racers. Fits T4.