Weighing just grams and packing smaller than a grapefruit, the Cerium Vest performs as a minimalist’s alpine midlayer or standalone in cool, dry conditions. Responsibly-sourced 850 fill down – with Coreloft™ synthetic utilized in areas prone to moisture – provides premium insulation, and the recycled 15D Arato™ nylon outer is light and durable. Streamlined in its design, it layers comfortably under a shell and easily fits into its included stuff sack for compact transport. Need a heavier option? Try the Cerium SV Vest .