These covers are functional, but have a couple of drawbacks.
1) there's a single nylon cord/drawstring running around the bottom of the cover---  I'd prefer to have a couple of eyelets so I could better fasten the cover. 
2) if the legs on your furniture have any kind of curvature, pulling the drawstring just makes it ride up the legs. 
The combination makes the covers loose and prone to blowing off... not in serious stormy weather, just the daily breeze that I get on my patio.  When these wear out, I won't buy the same thing agin