I was looking for something to put in two windows that are high on a foyer wall to help diffuse some sunlight. I didnt want draperies. My window wells are just over 40x40. These are just perfect for my European theme! My husband attached them with heavy double stick tape on the window sills and used the hangers at the top to anchor them to the inside window well.  I should note that the size is just shy of 39-12 square, which is less than what the description notes. Love them!