The SPRM5750 Robust Mount Shaft is part of Arkon's Robust Mount Series and can be used with 57mm (2.25 inch)-compatible adapters and holders, including those from Arkon as well as Ram Mounts and other third-party manufacturers. Create your own heavy-duty custom mount solution. This includes only the 5 inch Aluminum Mount Shaft Arm (holders and adapters sold separately) with tightening knob. The mount shaft measures 5 inches (127mm) tall, and along with your choice of mount head and base (sold separately), is ideal for creating a mount solution with ultimate flexibility with adjustment points on both ends of the mount. Use this mount shaft with Arkon's APCMAMPS57 57mm to AMPS adapter to create an AMPS mount.