The relyon bordeaux pocket 1800 mattress features pocketed springs that shape perfectly to your body contours due to each spring having its own independent action the upper layer of springs shape to the body contours while the lower layer absorbs changes in weight distribution for the ultimate in comfort and support the mattress also has a firm perimeter support which adds strength to the edge of the mattress to allow you to use the whole surface of the mattress as a sleeping areathe mattress