Genuine OEM Audi Synchronizer Hub Stop Ring, part number 020311331B. This critical component is part of the transmission's synchronizer assembly, designed to assist in smooth and precise gear engagement by matching the rotational speeds of gears before they mesh. It is located within the transmission gearbox, interacting with the synchronizer hub. Manufactured from durable, wear-resistant metal, it withstands the forces of gear changes. Using a genuine OEM synchronizer hub stop ring ensures the correct dimensions and material properties for reliable gear synchronization, which is vital for smooth shifting and transmission longevity.