this was the ceiling hook i remade to hang these 3d printed wrenches.Hook fixed should be printed with support, clean out as much support as you can from the middle but all of it is Not necessary. Insert nail into attachment, followed by the plug to keep nail in place. Slide hook attachment into Hook fixed and rotate until tight. make a pilot hole in the wall before trying to force hook onto wall because the nail might bend. Press and voila you're ready to hang what ever it is you are hanging...