Because the top shock retaining nut on VW and Audi FWD cars is recessed inside the strut tower; conventional methods for removing and installing it just won't work. The 1-3/4" long socket reaches down into the recess and fits the slot in the top of the nut. Center bore allows you to use a hex key to hold the strut shaft from turning; and the 7/8" (22mm) hex can gripped with a wrench.
