flex air pin box

I have the TraiAir. Before we put it on, I could watch the pinbox move up while the front cowl of the trailer was moving down when hitting rough road. All of that difference in direction was being absorbed by the frame of the trailer. With the TraiAir, the top of the TraiAir and the front cowl of the trailer move together. The lower half of the TraiAir moves with the truck and the top half moves with the trailer. Great invention, in my opinion. Would't want a 5er without one.