Genuine OEM Audi Coolant Regulator Housing with Thermostat, part number 03L121111AD. This integrated assembly is crucial for managing engine temperature by housing the thermostat and precisely regulating the flow of coolant through the engine's cooling system. It ensures the engine reaches and maintains its optimal operating temperature for efficiency and longevity. Made from durable black plastic, this unit weighs 0.303 kg. Genuine OEM thermostat assemblies provide exact temperature calibration and robust construction, preventing coolant leaks and ensuring reliable engine thermal management.