The Genuine BMW Rear Window Washer Valve - 61688391402 is a replacement part for the rear window washer system in BMW vehicles. It is a small, plastic valve that controls the flow of washer fluid to the rear window. This valve is essential for proper functioning of the rear window washer system and should be replaced if it becomes damaged or clogged. It is a genuine OEM part, ensuring the highest quality and compatibility with BMW vehicles. This product is designed to fit specific BMW models and should be installed by a professional mechanic for optimal performance.