Genuine OEM Audi Coolant Regulator, part number 059121111L. This essential component precisely controls the flow of coolant within the engine cooling system to maintain optimal operating temperature. Constructed with a durable plastic housing and a calibrated spring-loaded valve, it measures 0.28 meters in length. Installing a genuine OEM coolant regulator ensures accurate temperature regulation, preventing engine overheating or undercooling, and promoting efficient engine performance.