Get Schooled in the Geometry of Comfort Remember the trapezoid from 10th-grade geometry? Turns out, this funky ol shape is ideal for helping sleeping bag baffles retain heat. The trapezoidal baffle construction improves on our best-selling Cosmic sleeping bag-and it's just one of the reasons the Kelty Cosmic Down 0 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. Features Innovative trapezoidal baffle construction = thermal efficiency Lightweight and warm 550 fill down Environmental and health friendly C0 and PFC-free DWR fabrics Zippered internal stash pocket for headlamp, cell phone or actual stash Buttery-soft and durable 20D Nylon shell fabric Zipper draft tube with anti-snag zipper design makes it easy to get in and out Dual slider for ventilation with locking zippers Natural fit spacious footbox = more room to wiggle your toes Comes with stuff sack for quick departures Specifications Long ISO Comfort Rating: 17°F / -8°C ISO Limit Rating: 4°F / -16°C ISO Extreme Rating: -34°F / -37°C Fits to: 6' 6" / 198 cm Weight: 4 lb. 13 oz. / 2.18 kg Fill weight: 41.55 oz. / 1178 g Stuffed size: 10" x 19" / 25 x 48 cm Materials Insulation: 550FP Duck Down Shell material: 20D 400T Nylon Liner material: 50D 300T Polyester Source: Imported Kelty Cosmic 0 Deg 550 Down Sleeping Bag, Long Size, Right-Hand