The 4000 series elevates multi-layered spring technology to a highly advanced level. In addition to 3,000 dual-suspension pocket springsfor increased comfort and airflow, the mattress features a layer of 1,000 tablet springs each containing over 1,000 mini pockets. The 4000series also features luxurious material quality with lambswool, silk, memory wool and cashmere. The natural fillings work in harmony withadvanced technology to provide a softer feel without compromising the strength of the support. Three rows of hand side stitching areattached to the springs to enhance shape retention.