After much research, I finally ordered three of these to cover our two back windows and our door area on our deck, as the sun cooks our windows (we're in central Texas and it gets HOT in the summer). It has made a huge difference. We have both thermal curtains and thick blinds on the inside of the windows and still had a ton of heat coming in, which led me to have to keep all the curtains (even over the door) closed tightly all summer, thus "entombing" us. Well, now with these shades mounted on our eaves, blocking the sun's direct rays, I can open the curtains and get some natural light in. A godsend!