It comes with a big enough diameter to avoid stressig your filament much, yet is smal enough to even fit on a voron V0 printbed. It needs little filament for printing and no extra hardware for assembly. The little holes on its side, for holding your filament in place, are spaced frequent enough to keep it from unraveling. Its hight at 53mm is as big as a standard spool. 

Printing is best be done with 2 perimeters for walls, top and bottom. Lighning infill at 15-20% is also enough. You can print the whole thing with 0.2mm layer hight. Choosing 0.3mm hight and only 0.2mm for the threaded area works also fine. No support needed

The addidtional Power drill adapter makes it really easy to spoll the fiament neat and tight. This also comes handy for spooling filament direct from a big spool to the little sample reel.