Not one layer of springing but two in the luxurious duo comfort to ensure the most restful nights sleep we have built a double layer of springing in the mattress of this superb bed multiple layers of superior fillings combine with the springing to give the gentle firm support that duocomfort provides middot twin 135 gauge double heat treated open type spring middot flag stitched handles for ease of turning middot vents to allow the mattress to breathe middot multiple layers of high