Genuine OEM Toyota Radiator Hose, part number 165710Y121. This hose is responsible for transferring coolant between the engine and the radiator, playing a critical role in maintaining the engine's optimal operating temperature. It is typically located in the engine cooling system. Constructed from high-quality, heat-resistant rubber to ensure durability and prevent leaks under pressure. Genuine OEM hoses are engineered for precise fitment and flow characteristics, ensuring efficient cooling and preventing engine overheating.