The SPRM38MM Large Aluminum Mount Shaft is part of Arkon's Robust Mount Series and can be used with 38mm (1.5 inch)-compatible mount bases and heads to create your own custom mount solution. This includes only the Large Aluminum Mount Shaft (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 on both ends of the mount. Use this mount shaft with Arkon's APAMPS38MM adapter to create a 4-Hole AMPS mount.