The Genuine BMW Non-Return Valve - 64509418662 is a valve designed for use in BMW vehicles. It is used to prevent the backflow of fluids, such as fuel or oil, in the vehicle's fuel system. This valve is an original equipment manufacturer (OEM) part, meaning it is made by the same manufacturer that produces parts for BMW vehicles. It is a high-quality, durable valve that is specifically designed to fit and function in BMW vehicles. This non-return valve is essential for maintaining proper fuel flow and preventing potential damage to the vehicle's engine.