Do you mean the 'owner supplied' spreaders to keep the bug netting spread?
If so, mine are aluminum arrow shafts cut to exactly 16".
I sewed the outer edges of the outermost loops closed to create a pocket for the arrow shafts. A little bit of a pull to get the pocket over the end of the shaft and everything fits snugly. I also plugged each end of the shafts with a dowel rod - cut off very short - then sanded to a round nub - to avoid any sharp, abrasive edges in my pack.