SummaryMounts to Extrusion with M5 Machine screws and and holds your Original TAZ filament arm and allows it to pivot up, just like the original mounting style, only this one mounts on the outside of the Printer frame, and keeps the interior of the extrusion clear for a side panel enclosure. Part of the effort to clean up the profile of the machine for enclosing it. There are other nice options for holding the filament that do away with the pivoting arm entirely. This one keeps the arm and uses it, but changes the orientation.