by Frank
(Rochester, NY )
Shrunkin canvas....
You can use just one, but you would then need a pair of Align-a-zips on either side of the panel you lowered. Once the panel is lowered, as you have figured out, the side zippers will not align. Align-a-zips are sold in pairs, but keep in mind that like the EZ-Xtend zipper they add width. So you would need to be aware that unless your panels were too snug side to side, you will now have some excess slack. Good Question, thanks.
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