I'm sure it well be just a fixed pane window. That is what my Northern Lite has and there is no leaking.
I would like to have a slider for ventilation but I wouldn't want the leaking.
To some of the folks that think the window is a waste and it might be in their camper but I can actually look in my center rearview mirror and can see all the way out the back door and see what is behind me when I can't see it in my side mirrors. Some people in small cars like to get right up on my bumper and then I can't see them but with the center mirror I can. I know in the past with my AF1140 I was unable to see out of it as the slide was in the way.