Arkon's SPRMSWA 4.25 inch Robust Double Socket Swivel Shaft Arm features a swivel 360 degree center rotation. An octagonal design inside the shaft arm allows you to swivel the shaft arm to position the adjustment knobs for better access in tight spaces. Part of Arkon's Robust Mount Series, SPRMSRA provides double-ball rotation and is compatible with 25mm (1 inch)-compatible holders, cradles, and adapters to create your own custom mount solution. Use with Arkon's 25mm Robust Mount Series as well as RAM Mounts Size B components. This highly versatile mount shaft arm measures 4.25 inches (108mm) tall, and along with your choice of mount head and base (sold separately), you can create a double-ball mount solution with ultimate flexibility on both ends of the mount.