Yup, the internal one. It's pictured in the CD manual.
And as Bob states, he's definately correct regarding the proper tool.
Must admitt, I did not take the time to try to find a place that would rent the mercedes internal tool, and like usuall, I had so little time to get the work done I made do with what I could find.
But, considering the compression on that spring, correct tool is advisable.
In a perfect world I would have liked to use the official tool. Not sure (I think I know the answer, profit margin / or, discourage do it yourselfers) why benz tools are so crazy expensive.
I did use a piece of threaded stock placed down the middle of top mounting, spring, and control arm in-case the spring let go.
Scary proposition, I hate springs,