Vango nitestar 250 sleeping bag the mummy shaped sleeping bag offers a double layer of insulation for extra warmth a dof e recommended 2 3 season sleeping bag ideal for expedition use 210t diamond embossed polyester a strong 100 polyester with a diamond embossed design off set double layer construction off set seams prevent cold spots at the stitching lines single hole siliconised hollow fibre insulation increases durability maximises lofting potential for extra warmth and retains lof