We had a hard to shade area on our west facing small deck in the mountains (closer to the sun!).  This was the perfect solution.  
We have been looking for a solution for years and tried shade sails (too windy and no place for an extra support  pole) and umbrellas (rectangle too big), but nothing worked. We came across this umbrella online and immediately loved the shape of the umbrella, the ability to fasten this to the deck railing and the idea that folding this can be folded easily when not in use.

Thank you Wayfair.