Genuine OEM Audi Coolant Regulator Housing, part number 04L121026P. This component is a vital part of the engine cooling system, specifically designed to house the thermostat. Its primary function is to control the flow of engine coolant, directing it through the radiator or bypassing it to maintain the engine's optimal operating temperature. This housing is typically located near the engine block or cylinder head. Weighing approximately 0.522 kg, it is constructed from robust, heat-resistant materials to withstand high temperatures and pressures. Choosing a genuine OEM coolant regulator housing ensures precise dimensions, proper sealing surfaces, and material integrity, preventing coolant leaks and ensuring accurate temperature regulation for engine longevity.