The larger rectanglar unit in the photo is the replacement. My 2006 Ford is also a late 2006. It's interesting to me that recently Airstream has changed and is now installing the larger unit that Acubrake shipped to me after describing the problem and that fact that the engineer at Acubrake said that the other unit ( the one supplied with my 2007 Classic) did not have the proper software to accurately communicate with the factory Ford brake controller. If your Classic is like mine, the actuator is installed in the metal box between the A-frame. I had to modify the interior partition by cutting it in half with a cut off wheel in a grinder to house the larger actuator.It also reguired a different wiring harness . The harness in the factory installed actuator is hard wired the harness for the replacement heavy duty actuator plugs in to the back of the actuator.No big deal, the entire mods took about three hours. I had to repaint the inside of the box housing the actuator after doing the cutting and install straps to secure it in place and splice in the new wiring harness.As far as I've been told, Airstream is now using this heavy duty actuator as standard in the late year 2007 Classics.