Thumbscrew Top for standard M4 hex screw

This part fits into the top of a standard M4 hex screw, converting it to a thumbscrew - great for assemblies that need to be constantly adjusted. This was originally designed for use on a Folgertech 2020 Prusia i3, for the L bracket holding the filament spool in place (The original set screw was replaced by a standard M4 hex top screw). This allows spools to be easily swapped out