This antenna mast adjusts from 24" to 59" so it's able to mount in smaller attics, or extend it all the way out for outdoors to get maximum range from your antenna. The package includes a 2-1/4" wide base mount and a 4" wide wall mount to secure the mast to a rafter or outside wall. Mount the wall mount as far away from the base mount as possible for the best support. The three mast sections measure 1.4", 1.24", and 1.1" in diameter.