... are used to make the bed more durable.3) High density foam:You can have a choice from ... our own 30 types of foam selection.4) Leather swatches:top grain leather, ... 4 layers packing:non-woven fabric,peal cotton,more foam in the corners,lights,shelves,legs protection, ... . Each independently flexed coil is more sensitive to body contours and more durable than normal springs.2) This mattress ...