ENGINEERED DUAL LAYER SLEEPING SURFACE - Our 3-inch sleeping surface is comprised of a base layer of body-conforming lumbar support foam and a top layer of cooling gel memory foam. Specifically engineered for a cool, comfortable night's sleep. BODY CONFORMING LUMBAR SUPPORT FOAM - The base layer→ Designed to be firm enough to alleviate back pain but also forgiving enough to conform to your unique body type. COOLING GEL MEMORY FOAM - The top layer→ Engineered to dissipate heat and provide a cloud-like feel. PROPRIETARY TWIN XL MATTRESS WIDTH EXPANSION - Expand a Bed uses a patent-pending system of high-density foam side supports and tensioning straps to transform any Twin XL bed from a 38” width to a 46” width. Expand a Bed is designed for use with Full XL sheets. No special frame is required! UNMATCHED STABILITY - Our patent-pending strap system secures Expand a Bed directly to any standard Twin XL bed frame. This technology is explicitly designed to secure Expand a Bed and your Twin XL mattress in place, eliminating any annoying movements or shifts. EASY TO CLEAN WASHABLE COVER - Expand a Bed is wrapped in durable, water-resistant grey fabric for longevity and worry-free spills. Our industry-leading zipper system allows the top cover to be conveniently removed for easy machine washing. CONVENIENT STORAGE - Expand a Bed has the smallest storage footprint in the industry, ensuring hassle-free transportation and easy storage in any tight closet! Expand a Bed is delivered in a reusable vacuum seal bag allowing the product to be re-vacuum sealed and stored in a 16" x 16" x 24" bundle. Simply put Expand a Bed back in the bag when not in use and use a standard household vacuum to re-seal the product!