The DRX-3552 attaches to the front mirror bolt holes on the Cascadia giving you a sturdy, adjustable base for adding an aftermarket antenna system. The DX239 antenna stud was built to handle large trucker style antennas at highway speeds. The bracket is adjustable up to 40 degrees to help reduce reflections from the cab. They've also included their exclusive Square-Lock hardware that has a square shank that fits into the mounting bracket, keeping it from spinning, and allowing you to use a single wrench to tighten down.
Because of the low mounting location we recommend using antennas 5' or taller in height.