Genuine OEM Hyundai Engine Thermostat, part number 255002B400. This thermostat is a vital component in the engine cooling system, responsible for regulating the flow of coolant to maintain the engine's optimal operating temperature. It is positioned within the coolant circuit, typically near the engine block or cylinder head. Constructed from durable metal and rubber, it weighs approximately 0.105 kg and measures 76.87mm in length. Choosing a genuine OEM thermostat ensures accurate temperature calibration and reliable performance, crucial for engine longevity and efficiency.