The iSeries NXG3500 by Serta 13.5-inch mattress is a memory foam design built to deliver cooling comfort, pressure relief, and consistent support. This memory foam construction uses advanced materials to help reduce tossing and turning for a more restful night’s sleep. The split-head design can be paired with a compatible adjustable base to allow for independent head articulation, supporting personalized comfort and lifestyle needs. Its medium feel is ideal for back and side sleepers who want a balance of cushioning and support. NXG™ Memory Foam provides deep, contouring pressure relief, while Carbon Fiber Memory Foam helps channel heat away from the body for added comfort. A high-density foam core with Ultimate Edge™ Support offers durable, edge-to-edge stability across the mattress. The CoolFeel™ cover features a cool-to-the-touch surface designed to provide immediate cooling as you fall asleep. Mattress protector recommended.