Genuine OEM Hyundai Coolant Temperature O-Ring, part number 256232B000. This O-ring provides a critical seal for components within the engine cooling system, often used for coolant temperature sensors or housing connections, preventing fluid leaks. It is typically installed around a sensor or fitting to create a watertight seal. Made from a durable rubber compound, this O-ring measures approximately 60mm in diameter and 4.6mm in thickness. Using a genuine OEM O-ring ensures the correct material properties, precise dimensions, and resistance to engine coolant and temperature fluctuations, which are essential for preventing leaks and maintaining cooling system integrity.