1,Part Number: The D1S XENON HID ballast replacement part number is 7P5907381C or 7P5.907.381.C for reference to assist you easily find exactly what you need. 2,Ideal Application: The D1S XENON HID headlight ballast is especially designed replacement for Cayenne 2010‑2014 without PDLS or AFS option, please carefully confirm before purchasing. 3,Function: Designed to convert the voltage, stabilize the current, and protect the pulse surge to ensure that the headlights work in a safe environment and extend the life of the headlights. 4,Direct Installation: The xenon headlight ballast module is designed and produced on the base of standards, delivering plug and play installation without modification, coding or programming. 5,Reliable Materials: The superior D1S HID ballast unit is made from heavy duty aluminium alloy with stable performance, not easy to damage or break, anti aging and rust, durable.