Genuine OEM Audi Coolant Hose with Regulator Housing, part number 7M3121449A. This integrated assembly is a critical part of the engine cooling system, designed to manage coolant flow and connect various cooling components. The integrated regulator housing ensures precise control over coolant circulation. Using a genuine OEM hose and housing guarantees correct routing, resistance to high temperatures and pressures, and prevents leaks, which are all vital for maintaining engine temperature stability.