Breathe new life into your mattress and experience rejuvenating sleep with the Serta 4-Inch Renewal Memory Foam Topper. The two layers work together to give you the ultimate in comfort and support. A two-inch top layer of memory foam is designed to enhance breathability, keeping you comfortable throughout the night. This airflow design provides gentle cradling support and a therapeutic massage-like feel. A two-inch base foam layer provides support and extends the life of your existing mattress.