I bought two and put them in a country house. On a balcony door facing east, and every morning from six o'clock in the summer the sun beats down full on it, as they say. Behind it there is a bed where I lie down for my night sleep. Before I put up the Chios, with the shutters closed and conventional (dark-colored) curtains, I had a problem... After 6-7 in the morning I would wake up because I thought someone had turned on the light. As soon as I put these up, I was relieved. Good blackout (not total) and now I sleep like a baby without waking up suddenly. They also provide complete privacy both day and night. When they are drawn and you are outside, you cannot see into the house. For the money they cost, they are very good. I would like slightly better stitching, but okay, it's not a big issue. Also keep in mind that they are quite long at the bottom, resulting in a lot of fabric dragging on the ground. I could cut them, but I like that they are so long because the wind doesn't move them much. For a double balcony door, you should definitely get two and not one to do the job properly.