The Sea to Summit Trek Women's Down Sleeping Bag is a versatile down bag for all types of outdoor activities, including camping, backpacking, and trekking. The mummy style features a shaped hood and zipper draft tube to keep the cold out and the warmth in. Women's design features shorter length and narrower shoulders to increase thermal efficiency while down chambers are mapped to a woman's physiology to maximize warmth. Lofty 650 fill power duck down insulation (Responsible Down Standard certified) is treated with a non-PFC Ultra-Dry Down treatment to improve reaction to moisture, retaining loft and performance in rugged conditions. The relaxed mummy shape offers more room between the hips and knees for a natural sleeping position, while vertical baffles over the chest prevent the down fill from shifting during sleep. The Free-Flow Zip system allows you to open the bag sequentially for ventilation up to the point where it is opened flat as a quilt - you can even secure the snaps around your shoulders, open the footbox zipper and 'wear' the Trek around camp. Couple a Women's Trek to a Unisex Trek for the perfect two person sleep environment. The shell is made from recycled 20D nylon. The Sea to Summit Trek Women's Down Sleeping Bag is available in two sizes: Regular and Long and two temperature ratings: 30-Degree, and 15-Degree. Includes Ultra-Sil compression sack. Sea to Summit products are guaranteed against defects in materials or workmanship for the lifetime of the product.