Genuine OEM Volkswagen Upper Radiator Coolant Hose, part number 1K0121101BS. This essential hose is designed to carry hot coolant from the engine to the radiator, playing a critical role in the vehicle's thermal management system. It is positioned as the upper hose in the radiator assembly. Constructed from durable, heat-resistant rubber, it weighs approximately 0.203 kg and measures 0.335 meters in length. Choosing a genuine OEM coolant hose ensures precise fitment, correct routing geometry, and resistance to high temperatures and pressures, preventing leaks and maintaining optimal engine cooling.