Mattress Replacement - Beds That Raise Head End

[Orracle]

Hey, not sure how to word what I am trying to say in the title! I have a Winnebago Tour 42QD with the bed that must be pulled up and raises up the head end. My air mattress won't hold air any longer. I am wondering what people have put in to replace that which will still 'fold' when the bed is pulled up for slide retraction.

Thank you!