From Spandura: The Spandura Duffels utilize a large swath of a very unique fabric called Spandura. Literally spandex threads wrapped in Cordura, Spandura fabric has the durability of Cordura yet stretches like Spandex. Lining each side of the main zipper with this fabric allows these panels and the zipper to easily stretch and close over the worst overloads. Each duffle is lined with stiff foam so it keeps it shape for easy packing. Interior pockets and exterior end pockets for smaller items. These duffles are a must have for serious travelers. Available at the Spandura site.