The Stratosphere futon mattress from Otis is bench-built from the inside out to provide a level of quality, comfort and durability that is out of this world. Pressurized cotton less construction of 86% High Density convoluted and sheet foam along with 14% thermal bonded polyester to ensure long lasting comfort and support. Streamlined design which gives it the look and feel of an expensive futon mattress. The Stratosphere futon mattress is hand made assuring uniformity and quality control on each futon mattress.