Genuine OEM Volkswagen Engine Coolant Thermostat, part number 03H121113D. This component is crucial for maintaining the engine's optimal operating temperature by controlling coolant flow. It is typically located within the engine cooling system, often near the engine block or cylinder head. Weighing approximately 0.118 kg, this compact unit is designed for precise thermal regulation. Choosing a genuine OEM thermostat ensures accurate temperature calibration and reliable performance, preventing engine overheating or undercooling.