Filament guides for use with dimensional lumber shelves

These attach to the top of a standard 2x8 or 2x10 shelf with a single screw.  The bottom hole is sized for a snug fit 4mm OD PTFE tube .  Use a counter sink bit to chamfer the PTFE to make it easier to insert the filament.  

There are 9 files total.  Each one has a number to identify the spool.  This is easily painted in slicer for MMU.  

There is a small notch on the top in the center.  This will line up with the notch in the Prusa lack enclosure v2 spool holders to keep things aligned.  I have a remix of the spool holder as well with the same notch.