This is of the back wall. Rather than having a turban, We can install these about anywhere. They extend out from the shelter about 6" so you can attach PVC and run as needed. Mostly used in under slab installs. We refer to them as "vent nipples"
This is the flush mount option or what we call picture frame. It's used for flush in-slab installs in new construction. Being flush, it must have a roof above it.
Left is our emergency jack option. Rather than the side wall mount. You store it under the benches till needed then mounts into brackets in the center of the third step. It took up no room this way and gives about six inches more lift.