In the Rab Ascent 18 sleeping bag, warmth is provided by high-quality European duck down. The Ascent series uses durable yet lightweight shell fabricsideal for frequent camping and trekking. Ascent bags are not minimally narrow but feature the manufacturersWide Mummyshape: comfortable yet still warm for their weight. At the18 °C warmth category, EN-standard measurements no longer reliably indicate the extreme temperature differences between sleeping bags. Therefore, this bag lists only the comfort and limit temperatures, not the extreme rating. In any case, the extreme rating would be beyond40 °C. New! Ascent bags now feature a short zipper on the side opposite the main zipper, allowing you to stick your hand out for morning tasks or ventilation. Also new are the Grangers water-repellent down treatment and the L.O.F.T. baffle construction, which helps keep the down in place so that, for example, side sleepers dont experience cold spots at the hip or shoulder. - Men's regu