first I put down a layer of reflective foam.
Than I put down a layer of this plastic mesh designed to be used as a vapor barrier behind stucco. The idea here is air should be able to move through this layer, along with any moisture.
Than I bought a memory foam mattress off of amazon that is same thickness as factory mattress. (before I also had MF topper on factory mattress and it got in the way of cabinet opening.
(picture shows size of box its shipped in)
This was all in my Wolf Creek, but when we bought our Arctic Fox we transferred everything into the AF, and put the brand new mattress from the AF into the Wolf Creek we were trading in. This way whom ever bought our old WC got a brand new, factory sealed Mattress :)