plastic shields around 603.971 injectors?
 

I noticed the SD #6 injector has a plastic shield around it. The shield has splines to mesh with the lockring. It's a directional shield meaning that you can clock it along the splines. I recall some discussion on this shield but I can't find it in the archives. Anyone know what this shield is for?

Thanks,
Sixto
93 300SD

Not sure what it was used for, but I know that MB USA has discontinued the part. Tried to get a set a few weeks back as mine had broken apart after last injector rebuild..stealership showed them as deprecated.