Genuine OEM Volkswagen Coolant Regulator Housing, part number 07Z121111. This critical component houses the engine's thermostat and plays a key role in regulating the flow of coolant throughout the cooling system. It is typically located at a junction point in the engine's coolant passages. Constructed from durable metal, it weighs 0.7 kg. Using a genuine OEM housing ensures precise fitment, proper sealing, and reliable operation of the thermostat, which is vital for maintaining optimal engine operating temperatures and preventing overheating or undercooling.