Genuine OEM Volkswagen Roof Water Drain Valve, part number 10A877236. This small but critical valve is responsible for controlling the efficient drainage of water from the vehicle's roof or sunroof system. It is typically located within the roof structure, connected to the drain hoses. Weighing only 0.015 kg, it is designed to prevent blockages and backflow. A genuine OEM drain valve ensures correct flow characteristics and material resistance to water and debris, preventing costly water damage to the interior and electrical components.