Genuine OEM Audi breather line, part number 420103211. This line is a critical component of the crankcase ventilation system, designed to manage internal engine pressures effectively. It is positioned within the engine assembly as indicated in the diagram. Constructed from high-grade materials, this line ensures resistance to oil vapors and heat. Genuine OEM parts are vital for breather lines to ensure correct routing and secure connections, preventing vacuum leaks and maintaining optimal engine performance.