These are the coolest thing.  I bought them for my son's room, as curtains fell close to his bed and would get tangled in his bedding, with the height of our windows.  I am probably late to the game, as I didn't realize these were a thing before.  These are easy to install, as the measurements don't have to be super accurate to have the shade hang in the center of the window, as there is a little give in the screw holes.  You can actually raise and lower these things with a finger and there are no strings in the way. I got more for my other son's bedroom.