Genuine OEM Audi flange shaft, part number 0CS409355B. This component acts as a critical interface for power transmission between the transmission output and the drivetrain assembly. It is precision-machined to ensure a secure fit with the differential and axle components. Genuine OEM flange shafts are manufactured to exact metallurgical tolerances and spline specifications, which are vital for preventing vibration, minimizing drivetrain lash, and ensuring a long service life under high torque loads.