The Western Mountaineering Flight Jacket shell fabric is a tightly woven material that weighs only 0.9 oz. per square yard! 5.25 ounces of 850 plus fill power goose down, with a total average weight 10.5 ounces in a medium. If you are looking for a lightweight, compact, and highly insulative layer, then look no further. This is the lightest down garment you will find with this warmth to weight ratio. To top it all of, American made too. Elastic drawcord bottom closure Down filled front pockets. Inside pocket doubles as stuff sack Super light coil zipper Down filled draft tube behind zipper Made in U.S.A. Western Mountaineering Men&';s Jacket & Vest Sizes Size