Genuine OEM Audi Thermostat Housing, part number 077121121D. This cast metal component is integral to the engine cooling system, providing a secure enclosure for the thermostat and directing the flow of coolant. It ensures the thermostat operates effectively to regulate engine temperature. The housing weighs 0.663 kg and measures approximately 0.29 meters in length. Choosing a genuine OEM thermostat housing guarantees precise dimensions, proper sealing surfaces, and durable construction for leak-free and efficient cooling system performance.