This picture shows the conveyor tower from the kit. The windows at the top of the tower had to be built from scale lumber that was provided. Looking back on this process I think that the tower would look a little better if I would have replaced these windows with Grandt Line windows. But if you, like myself, want to build the windows, I suggest copying the window templates from the instructions and then gluing the lumber directly to the plans. This gives the windows some added strength and also helps to keep things square.