Genuine OEM Audi Air Conditioning Check Valve, part number 4M0816806. This valve is crucial for controlling the unidirectional flow of refrigerant within the vehicle's air conditioning system, preventing backflow and maintaining system pressure. It is integrated into the refrigerant line assembly. Weighing 0.116 kg and measuring approximately 60mm in length, this component is engineered for precise fitment. Choosing a genuine OEM check valve ensures correct refrigerant flow characteristics and material compatibility, vital for the efficiency and longevity of the entire A/C system.