Gear differential inside gears accuracy produced from new graphite composite mixture. Includes 2 bevel gears + 4 satellite gears. Molded from an all-new unique lightweight and extra-strong graphite material provides gears an optimal security of hardness, toughness, and freedom to supply endurance, minimal use, and minimizing breakage or teeth stripping. The lighter, graphite gears end up in increased drivetrain effectiveness. A must have for expert racers. Fits XB4, NT1 & T3 cars.