4X Upgrade Aluminum Insert Fuel Injector Cups For VW Polo 9N Jetta MK4 Passat 3B
For VW Polo 9N 2005 - 2010. For VW Jetta MK4 2000 - 2005. These are Billet aluminum inserts that are screwed into the injector opening on the fuel rail. They hold the injector in the correct position in the fuel rail for a proper spray.