Genuine OEM Volkswagen socket head bolt, part number N91190901. This precision fastener is designed for use in the engine cooling system, specifically for securing coolant pipes and distribution flanges. Its socket head design is ideal for installations where space is limited and high torque accuracy is necessary. The bolt is treated for corrosion resistance to withstand the harsh environment of the engine bay. Genuine OEM fasteners ensure a perfect fit and maintain the integrity of the cooling circuit over time. This bolt is critical for ensuring that pressurized coolant components remain securely attached.