Proven across a range of alpine missions and backcountry adventures, the Cerium packs small, weighs little, and delivers big warmth. The design – refined for optimal fit and efficiency – utilizes more sustainable materials while delivering the same outstanding warmth-to-weight ratio. Responsibly-sourced 850 fill down – with Coreloft™ synthetic utilized in areas prone to moisture – provides premium insulation. The recycled 15D Arato™ nylon outer is light and durable, the bio-derived liner reduces petroleum use, and the streamlined design is articulated for freedom of movement. As an alternative to down fill insulation, we also offer synthetic fill products, such as the Atom Jacket.