We don't have the installation guide out just yet, but the below pictures and description should be all you need until it's published.
Looking at the attached pictures below, you can see that there is a center hollow post where the pigtails come up. That post has a diameter of 1", and the threaded nut with a bezel on the bottom that is 1.5" in diameter (or 38mm wide). You would drill or cut a circular hole of that diameter in a ceiling tile or ceiling or wall element, and insert the antenna post on one side, and thread down the nut with the 1.5" bezel to sit inside the hole.
There is also a standoff bracket provided as part of the kit, should you need to surface mount the antenna and/or are no means to penetrate the wall to drill a 1.5" hole.
Below is a front and back picture of the antenna as well.