Thanks Coot. I'll look into it when I get home since I better be in my driveway when I learn how to adjust the rings.
As for today, it looks like I may be able to tie down the the ends with the perpendicular end pieces that are attached to the center of the roller topper. Now I see why all the other rv'ers have 8 ft step ladders tied to their roof ladders. Got'a love the camping projects!