Get Schooled in the Geometry of ComfortRemember the trapezoid from 10th-grade geometry? Turns out, this funky ol shape is ideal for helping sleeping bag baffles retain heat. The women's specific Cosmic features trapezoidal baffle construction for increased thermal efficiency-and it's just one of the reasons the Kelty Women's Cosmic Down 20 is still our favorite three-season superstar. We also love the natural-fit foot box for happier feet, and a PFC-free water-repellent coating for a healthier environment.What makes it a women's bag? It's designed for and tested to women's specific ISO standards. Studies show that women "sleep colder" than men. So, in addition to narrower shoulders, wider hips and a shorter torso, our women's bags have extra insulation in the upper body and footbox.FeaturesInnovative trapezoidal baffle construction = thermal efficiencyLightweight and warm 550 fill downEnvironmental and health friendly C0 and PFC-free DWR fabricsZippered internal stash pocket for headlamp, cell phone or actual stashButtery-soft and durable 20D Nylon shell fabricZipper draft tube with anti-snag zipper design makes it easy to get in and outDual slider for ventilation with locking zippersNatural fit spacious footbox = more room to wiggle your toesComes with stuff sack for quick departuresSpecificationsISO Extreme Rating: -22° / -30°CISO Limit Rating: 13° / -11°CISO Comfort Rating: 25° / -4°CFits to: 5' 8" / 172 cmWeight: 3 lb. 7 oz. / 1.56 kgFill weight: 30.62 oz. / 868 gStuffed size: 8" x 13" / 20 x 33 cmMaterialsInsulation: 550FP Duck DownShell material: 20D 400T NylonLiner material: 50D 300T PolyesterSource: Imported Kelty Women's Cosmic 20 Deg 550 Down Sleeping Bag, Regular Size, Right-Hand