Genuine OEM Audi Coolant Hose, part number 04L121157. This hose is a critical component of the engine cooling system, responsible for the efficient transport of coolant between engine modules. It is engineered to withstand high pressure and extreme temperature fluctuations without deforming or leaking. The hose features pre-moulded geometry to ensure correct routing and clearance within the engine bay. Genuine OEM coolant hoses are essential for maintaining proper cooling system pressure and preventing premature failure due to fluid incompatibility or heat degradation.