Genuine OEM Audi Engine Coolant Thermostat Kit, part number 079121115BK. This critical component regulates the flow of coolant throughout the engine to maintain optimal operating temperature. It is typically located within the engine's cooling system, often near the water pump or cylinder head. Weighing approximately 0.437 kg, this assembly is designed for precise temperature control. Using a genuine OEM thermostat ensures accurate temperature regulation and prevents engine overheating or undercooling, which can lead to premature wear or damage.