That's because you can fully enclose your shelter if you so choose using one convenient package. The package consists of two 13-foot white sidewalls, one white endwall, and one white zippered end wall. The two sidewalls and endwall totally enclose three sides of the tent, and the zippered endwall does the same, but allows for easy entry and exit using the handy zipper.
High-wind conditions, occasions where rain is coming into the canopy from the sides, and times when you want a little added privacy are perfect applications for this package. People use this set of sidewalls at tailgates, outdoor dinners and celebrations, at business expos and trade fairs, and elsewhere. There are tons of uses that aren't listed, so many owners come up with their own places to apply this package.
Your precise use for this setup isn't nearly as important as being aware that you're probably going to have a use for it at some point. There's nothing worse than getting where you're going only to find out that you don't have the right equipment. You'll never have that problem, and you'll always be prepared for whatever the weather or the situation calls for when you take a Complete 10 x 13 White Wall Package with you and your King Canopy wherever you go.