Allergen Protect™ Protects the mattress from common allergens, such as dust mites, helping it stay fresh and healthy. Zone Support High-density foam center provides power-packed body support in the center third of the mattress, reducing body impressions and providing additional support to the lower back allowing muscles to relax and recover Pressure Relieving Foams StayTrue™ comfort layers make up the foundation of your mattress comfort fillings to support your body with different comforts. Duraflex™ Reinforced Edge Support High-density foam border inserts support the edge of the spring system, provide a firm seating edge, and increase the sleeping area. Exclusive Double Offset Spring System works with a hinging action to deliver correct back support with no roll-together.  Originall designed by doctors