Be fully aware that you need 3 attaching points for a triangular sun sail to be hung and you will need them to be high enough so that it doesn’t droop too low.  You will need to continually adjust the 3 points in order to get the sail fully expanded.  In this case of a 16’ sun sail I was able to attach the point of the sail to the edge of our patio and the other 2 points between the expanse of 2 trees.  It wasn’t easy.  What I learned was the larger the sun sail the more difficult it is to find attachment spots to get it to hang properly.