This is the retaining ring that keeps your Xenon bulb in the housing. They can often get lost or broken when removing or installing a replacement bulb. It used to be that the only solution was to comb through junkyards looking for a replacement. Now, Euromotiv has your solution.

From Genuine VW/Audi comes this piece for your HID system. It secures your bulb in the housing and is great as a replacement or a part for a retrofit.

Check Euromotiv's website to see all of the parts available for your HID system.