Prior to the Fourth Arrow System outdoor videographers would buy a two section or a three section camera arm- depending on their needs. New for 2017 is the Fourth Arrow Extension Arm. For the first time videographers can add an arm section on the fly. Transform your standard Fourth Arrow two section arm to a three arm section when needed- ideal for self filming! When in use the extension arm allows 47.5 inches of reach. It comes with knob used to lock initial section in place.