As you can see from my picture, when these blinds are down, they really darken. Mine leave a sliver of light coming in, but that is because they are inside mounted. Hanging was a breeze. Operation is a dream, and there are no cords. I like the handle that is on them, so you are not grabbing the actual blind to operate them. My teen sons like rooms so dark they are like caves. I need to order more for another sons room.