cv boot slider?
The problem is the MBZ boots are held on with a special crimp on the big ends and not a band clamp. It takes a very expensive tool ($1500!) to make that crimp, and the half shaft has to be out of the car to do it.
I have never heard good words about using the 'repair kit' which is a split boot that glues together. While they do work well on other car (like Fords), they do not seem to hold up on the MBZ joints. Not sure why.