Identify the bottom section which has a small strip of foam at the back and two folded metal ribs
at either edge. Place the bottom section on your work surface with the foam strip away from
you. Note -
you should now be standing on the ‘In” side of the wall sleeve.
Orient the side sections such that the 4 large, keyed holes on the flanges are on the outside and
the six smaller holes are on the inside.
“Out” side
”In” Side
