There is no mattress, only a thin (1/4" or less) pad.  I will need to purchase an additional air mattress or foam mattress to make this usable.  Even for a camping trip, additional padding/mattress would be needed.   It appears to be sturdy and stable.  It is wide enough for a relatively thin person, but I doubt that a larger individual would be comfortable, in spite of the weight rating for 400+ lbs.