An apparatus comprising a driven element, a driving element operably coupled to the driven element, and a shield coupled to the driving element such that the shield at least partially covers at least one of the driven element and the driving element. The driven element includes a housing with an outer surface. The outer surface has a first raised portion and a first non-raised portion, the first non-raised portion at least partially surrounding the first raised portion, the first raised and first non-raised portions define a first surface pattern. The shield has an outer surface with a second raised portion and a second non-raised portion. The second non-raised portion at least partially surrounds the second raised portion, defining a second surface pattern substantially similar to the first surface pattern.