【Higher Quality】Machined from a single piece of billet aluminum for greater strength, it does away with the weak plastic factory cover.
【Enhanced Aesthetics】The surface is anodized to add color to your engine bay and upgrade the appearance of the engine bay.
【Precision Engineering】High accuracy ensured by latest-generation CNC technology.
【Easy Installation】These coolant caps retain all of the factory provisions by simply allowing you to snap the factory pressure-relief into the new billet aluminum cap.
【Replacement Part Number】17117639020, 17117521071.
【Note】Please watch installation video before installing. The built-in components of the stock coolant reservoir cap are required to ensure a proper seal during installation. These do require assembly and swapping the pressure relief valves from your old caps to your new billet caps. Will not compatible with E9X M3, F8X M2 M3 M4, F10 530i 550i and M5 vehicle.