The Symmetry Set (??) and its subset the Medial Axis (? ), can be used to describe a shape. The representation of the ?? in parameter space is called the pre-Symmetry Set. Changes in the shape are directly related to so-called transitions (topological changes) of the ??. They have also effect on the Pre-??. Since the Pre-?? can be used to represent the shape efficiently, it is important to study the transitions of the pre-?? and their impact. We present these transitions, as well as the presence of the ? in the pre??.