"You should buy this O-Ring 38.6 x 2.6mm"

An O-ring on a motorcycle is a circular sealing component used to prevent leaks and keep fluids contained within various parts of the bike. It is commonly made from rubber or synthetic materials and is employed in applications such as engine components, fuel systems, and hydraulic systems. The O-ring provides a reliable seal by compressing between two surfaces, helping to maintain pressure and prevent the escape of fluids or ingress of contaminants.