Feature: 1. Applicable Model: Xenon ballast control module is fit for A1 2011 To 2014; fit for 718 981 Boxster Cayman GT4, for Cayenne E2; replacement for Tesla Model S. 2. OE Number: The part numbers for reference are W003T22171, 8K0941597F, 8K0.941.597.F, please confirm whether it is consistent with the OE you need. 3. Stabilize Light Current: Uses advanced microelectronics technology and CNC manufacturing to provide precise control and stability for the lamp working current, ensuring lasting and stable performance. 4. Improve Driving Safety: By controlling and stabilizing the working current of the lamp, it provides brighter and more stable lamp brightness, improves the night driving vision, and provides a better driving experience. 5. Direct Replace: Designed and manufactured according to the original sizes, can be used to refurbish and replace the old and broken headlight ballast. Specification: Item Type: Xenon Headlight Control ModulePart Number: W003T22171, 8K0941597F, 8K0.941.597.F Installation Mode: Replace installation directlyFitment:Fit for A1; for Caddy; Replacement for Tesla Model S; for 718 981 Boxster Cayman GT4, for Cayenne E2 Fit for A1 2011-2014 Fit for Cabrio 2013-2016 Fit for Caddy 2015-. Package List: 1 x Xenon Headlight Control Module Note: Please double check the part number and fitment of your item, matching information is for reference only.