These are hollow "Peg Links" that interconnect, to allow the wire to pass up the middle. Print 1 fan top and one base, then as many "Plinks" as needed, pass the wire through the hole in the fan top, before connection the fan, then through each link, before snapping them together...V1.11 - fit is a little more snug, also mount tabs are wider, and added a new bottom tab mount...V1.12 - Fan Mount Break Off Tabs needed rafts