J-Life Japanese Traditional Shiki Futon - TWIN SIZE (shikibuton) Traditional Japanese Futon (Twin - 39" x 75") 5-Year Manufacturers Warranty 4 Inch Cotton Mattress Adds Portability and Firm Comfort. Made With a Durable 6.5 ounce natural cotton/poly duck outer material (unbleached). No foam, wool or innersprings.