I bought this dog door to go through my wall. Since my walls are 11" thick, the door is too small for my boys. I had to buy the next size up and can't return this one. If anyone can use it, I am happy to give it away. I am located 20 min west of Philly. If you are interested, go to the website to see if it will fit your dogs needs. It is a great dog door with dual flaps. This model will go through a wall or a door. If you install it into a door, it will fit the standard Havanese. If you are going through a thick wall like mine, it will only fit a small have 8.5-9 at the withers.