Classic 6 Inch Gel Memory Foam Mattress (Twin) 6 inch twin memory foam mattress with a zipper cover to remove and wash. perfect for kids, bunk beds etc. Mattress layers include, 1.5" premium memory foam, 4.5" high-density foam 25 year warranty CertiPUR-US Certified Allow 48 hours for the memory bedding to expand to its proper size and shape. This Mattress is shipped in a small box and is compressed.