Offering the perfect backpacking balance of comfort vs weight, our Altitude™ Series sleeping bags have more space than traditional mummy bags, yet still provide the thermal efficiency you need when exploring above the tree-line. The Free-Flow triple-zip design provides multiple ventilation options: the half zip on the left side of the bag provides freedom of movement for both arms, additional ventilation and allows the top third of the bag to be folded down. The full length, two-way right side zip and separate foot zip transform the bag into a full quilt. High quality 750+ Loft down, oversized draft tubes, shaped footbox and 3-dimensional hood all retain body heat. The Altitude™ also features a greater fill weight of ULTRA-DRY Down™ boosted by a layer of THERMOLITE insulation in the footbox for instant warmth. Vertical baffles over the chest section ensure the down insulation cannot shift to the outside of the bag during sleep, creating cold spots. A side block baffle construction maintains the 60/40 fill ratio, keeping more down on the top of the bag. Our technical tapered rectangular design is a great alternative to constrictive mummy shapes. It allows you to move inside the bag and adopt a natural sleeping position without compressing the insulation. The women’s specific fit is wider at the hip and narrower at the shoulder and comes in two lengths.Features• Women’s specific technical tapered rectangular shape for perfect balance of space and adaptable warmth• Extra down overall and THERMOLITE panels under the foot area for additional warmth• Super-light 20D Nylon shell and lining fabrics for minimal packed size and maximum breathability• RDS 750+ Loft ULTRA-DRY Down™• Vertical chest baffles prevent down migration and cold spots• Free-Flow half left side, full length 2 way #5 YKK right side and separate foot zips fallow maximum ventilation and use as a quilt• Oversized draft tube with anti-snag materials• Oversized neck draft tube with dual adjustment system• Generously sized hood and dual cord adjustment for maximum warmth retention• Anatomically shaped footbox allows maximum down lofting• Large internal security pocket• Includes Ultra-Sil™ Compression Bag for compact storage• Zip Coupling: This bag is designed to zip with anotherSpecifications• Max user height: < 170 cm / 5' 7''• Girth:Shoulder: 148 cm (58“)Hip: 148 cm (58“)Foot: 118 cm (46“)• Fill weight: 25 oz / 720g• Weight: 2 lbs 14 oz / 1294g• Temperature:Comfort: 15°F / -10°CLower limit: 1°F / -17°CExtreme: -37°F / -38°C.