We have always been after very hot in the summer in the attic and in the stairwell, now a heat protection of Velux gained us. The installation was very easy, as all the windows Velux prepared already for extensions. DC the following week it was sunny and warm; and the heat shield has a lot held. It is still something would druch; but on the top floor there is now only "very warm" and in the hallway and even on the 1st floor (of below it) prevail much more pleasant temperatures. The summer can come!