The nylon ring for a rear wheel bolt of a Citroen DS is a specially designed plastic ring that helps prevent corrosion and wear. It provides a firm seal and dampens vibrations, resulting in a smoother ride and less maintenance of the wheel suspension system. This ring is essential for the durability and reliability of the vehicle, especially in older models such as the classic Citroen DS. By ensuring the bolt is securely fastened, it reduces the risk of damage during rides on rough roads or at higher speeds. It is an indispensable part for classic car enthusiasts and restorers.