It is ok if U have a smaller wall( less than 5 " thick--I attempted to use on my wall but ended up using wood paneling to make sides/bottom

I've installed other dog doors into walls in the past but never had this piece to make it a clean install. This unit is helpful in making the passage through the wall clean and weather proof. My wall was the narrower width. They had the product marked so that you can just break away the portions for a narrower wall. It installed great. My only issue was with the bolts that were provided - they recommend cutting them to shorten them for the narrower wall. I used a washer that held the longer screw back so that I didn't need to cut it. I've had issues with bad threads after cutting bolts so didn't want to go there.

My Husband and myself were disappointed in this wall kit unit....It didn't fix well in the insulated dog flap door which was to be used with....We need tthis because we were putting dog door in a outter wall 6 inches thick....but the wall kit is to small all the way around the inner wall for the insulated doggie door....Very disppointedis in this product....