Vent rear view assembly

This view will show you how the threaded rods go through the insert that is injected molded into the face plate and how the hex lock nuts are attached, threaded up to the back of the face plate.  The threaded rods then go to the back of the foundation.  The backer bar, which has 2 holes in it is then slid onto the threaded rods, then catches the back of the foundation.  Once the wing nuts are screwed on behind the backer bar, it would pull the face plate up tight to the front of the foundation with a generous supply of clear latex caulk placed on the back side of the face plate.  When the wing nuts are tightened it provides for a permanent seal.