Stiffer Side for Sitting
So simple are some solutions to common problems, not much engineering is needed here. What is needed to make a mattress last is an edge that is stiffer than the rest of the mattress. We call it "rail foam" because it lays along the sides of the mattress like a rail; a firm rail. Keeping you in the bed. Keeping you sitting firmly on the edge of the mattress without sliding out.
Only Fleet Mattress has this truckers edge.