The alpine-ready midlayer in cold conditions, a warming layer during rest phases this is the Arc'teryx Cerium Women's Jacket for women who prefer a layering piece without a hood. Tailored to a skimming fit with articulated patterning for movement this packs a wallop of warmth in an airy 225 gram package. Body mapped insulation places Coreloft™ synthetic in areas prone to moisture so you can enjoy the feathery warmth of down without worrying about losing loft. The 15D Arato™ nylon outer is light and durable, while the inner liner fabric is made from a bio-derived material from castor oil. This is so light and packable.. it comes with its own stuff sack. From winter ski trips to summer summits this is a featherlight performance layer with a beautiful fit, plenty of movement, and built for layering under a shell for a maximum impact of warmth with a minimal amount of bulk.