I printed Vezkah's Printrbot Spool holder only to find that my spool differed from the type the design was intended for, My spool was hollow. So I Printed this sleeve so i could still make use of the following part http://www.thingiverse.com/thing:329569 the sleeve fits into the spools centre and provides a surface for the holder to support. Thanks to Vezkah for an awesome easy print solution for the Printrbot Metal!