A premium 800-fill goose down, 40 degree sleeping bag that offers superior warmth, unmatched comfort and versatility, coupled with lite-weight construction and a female-specific fit. The waterproof Pertex® Endurance Arid Zones™ at the head and foot of the bag protect against condensation in critical areas. The wider mummy shape provides more room and the full-length side zippers allow the female and male bags to zip together for your snuggling enjoyment. Sleeping Bag Specs Rating: 40 deg F | 4 deg C 1 lb 5 oz. | 600 g Still the warmest and most compressible insulation available GoLite uses premium quality 800- and 600-fill power goose down. Down is still the most thermally efficient insulation available, i.e. it provides more warmth for its weight than any other insulation available. Down is also superior in its drape, comfort, lifespan, and compressibility. Nature is an incredible thing. Unmatched warmth-to-weight ratio: down’s fine filaments reach out into its surroundings and create dead air space that slows the escape of warm air, doing it better than any synthetic. More compressible and durable than synthetic insulations, and it retains its loft better over time. Features 6" sewn-thru construction compartments with 3" loft Sewn-thru construction hood with drawcord Uses Mild weather overnights