Genuine OEM Audi Rear Engine Breather Line, part number 4G0121081EL. This line is a critical component for engine ventilation, designed to allow crankcase gases to escape, preventing pressure buildup. It is positioned at the rear of the engine, connecting to the crankcase ventilation system. This flexible line measures approximately 0.525 meters in length and weighs 0.0297 kg. Using a genuine OEM breather line ensures correct routing, proper sealing, and resistance to oil and fuel vapors, which are essential for maintaining engine health and emissions compliance.