As light and compressible as functionally possible, the Cerium SL down vest weighs a scant 125g (4.4 oz) but delivers exceptional warmth for its weight. The 850 fill power goose down's warmth to weight ratio is outstanding, and the tear-resistant, wind resistant Arato 7 nylon shell is exceedingly lightweight. It primarily functions as a mid layer, but its efficient warmth and packability makes it an effective standalone for rest breaks, or evenings at camp. Trim fit, hip length. Down Composite Mapping strategically places both down and synthetic insulation. Lightweight, minimal front and chest pocket zippers, stuff sack included. Adjustable hem drawcord seals out cold.