A climb in the Mont Blanc massif can blend four seasons in a single day. Our Ultralight Down Vest will block the wind and trap core warmth when temperatures plunge. High-lofting, extremely compressible 800-fill-power 100% Traceable Down (European goose down that can be traced back to birds that were never force-fed, never live-plucked) is encased in an ultralight nylon ripstop shell that's tough for its weight and sheds moisture with a DWR (durable water repellent) finish. Variegated channel construction creates a thin, thermally efficient silhouette that uses less down to trap your heat; the vest slides easily over light layers or under a shell and stuffs into the left handwarmer pocket to create a travel pillow. With two zippered handwarmer pockets and a drawcord hem.