The Kingsdown Prime Merrivale Mattress Collection gives you a coil on coil mattress at an incredible price. Individually Wrapped Coils, arranged into three zones - a denser gauge coil surrounds the border of the mattress for a firmer edge, the lightest gauge coils inside for comfort and support, with a density between the two in your lumbar area for greater support. A second layer of Micro-Coils in a lighter gauge for added cushion. Poly Gel is used in the quilt for a cooling, fresh feel. Adaptive foam in the lumbar region forms to your shape for added back support.