About the XL Twin Otis Zone 5 Stretch out and relax on this extra long mattress with medium firmness. Made with multi-density foam layers this mattress is resilient and will keep its comfort. Six layers of foam fill the Belgian damask shell. The foam filling conforms to your body shape as you lie down. The fabric`s tailored edges will last for years. The exclusive Otis Comfort Lock Cushioning System tensions the material inside to create a consistent comfort level over the life of the mattress