Genuine OEM Volkswagen Flywheel, part number 03L105266BS. This heavy rotating disc is bolted to the end of the crankshaft. It serves to smooth out the power pulses from the engine, store rotational energy, and provide a friction surface for the clutch. Its precise mass and balance are critical for smooth engine operation and efficient power transfer to the transmission. Genuine OEM flywheels are manufactured to exact tolerances for optimal performance and durability.