Zinus Cool Gel Memory Foam 5 Inch Sleeper Sofa Mattress, Replacement Sofa Bed Mattress, Twin 5 inch mattress with 1 inch of Gel Memory Foam and 4 inches of High-density Base Support Foam Only the Highest Quality Foam  Foam is CertiPUR-US Certified for durability, performance, and content Worry free 5 year limited warranty Smartly Shipped - Our patented technology allows our mattress toppers to be efficiently compressed, rolled and shipped in a box conveniently to your door Replacement mattress only, sofa bed is not included