The 13.5’’ iSeries NXG 3500 Medium mattress by Serta® represents the most elevated all-foam design in the collection, offering a balanced medium feel ideal for all sleep positions. Designed with wellness in mind, it promotes healthy spinal alignment, reduces tossing and turning, and supports more restorative rest. NXG™ Memory Foam delivers premium contouring pressure relief with a slow-response feel that cradles every curve. Carbon Fiber Memory Foam enhances strength and stability while channeling heat away from the body for a cooler night’s sleep. A high-density foam core with Ultimate Edge® Support ensures lasting durability and reinforced performance from edge to edge. The cool-to-the-touch MaxCold™ cover provides immediate cooling comfort, elevating the sleep experience with a refreshing surface feel. Mattress protector recommended. Compatible with most adjustable bases.