With obsessive attention to detail, Arc'Teryx has refined the design, used durable materials and maintained an exceptional warmth-to-weight ratio. Responsibly sourced 850-fill down - with Coreloft™ synthetic used in areas prone to moisture - provides premium insulation. The exterior - recycled 15D Arato™ nylon - is lightweight and durable, a bio-sourced lining reduces the use of petroleum, and an insulated StormHood™ provides added protection.