The DRX-3552 antenna mount is designed to fit 2017-Up Freightliner P4 Cascadia trucks. The bracket is constructed of 5 gauge aircraft aluminum and easily attaches to the mirror arm on the driver or passenger side without drilling holes. The forward angle of the mount can be adjusted 40 degrees to obtain optimal performance. The DX239 stud is encased in ABS plastic with a 1" stainless hex base and 3/8"-24 thread SO239 stud. Driver Extreme square-lock hardware ensures professional installation, built to provide years of superior performance.