Genuine OEM Audi Power Steering Fluid Reservoir, part number 420422371B. This container is a critical component of the power steering system, designed to hold and supply hydraulic fluid to the power steering pump. It ensures a consistent fluid level and allows for thermal expansion. Weighing approximately 0.5 kg, this reservoir is made from durable plastic. Using a genuine OEM reservoir guarantees proper fitment, material compatibility with power steering fluid, and reliable sealing to prevent leaks and maintain system integrity.