The bench is a really cool custom piece that we made for the van. When in bench mode, the two small cushions are the backrest while a large cushion is the bottom support.
When switched to bed mode, a platform mounted on heavy duty drawer slides pulls out to double in size. The bed is about the size of a queen.
Technical Details: The bench is made from ¾” 5 ply birch plywood and pine framing. The slide is 28 x 69” supported by 28” 500 lb. rated drawer slides on each end. This places quite a bit of torsion on the side walls of the bench, so the sides are made of 2.25” thick birch plywood. The bench does not budge when both of us sit on the edge.