Our First Ascent guide team built this ultralight jacket for alpine climbing in cool to cold weather. Windproof ripstop polyester shell. Each cluster of the super high-loft 800 fill StormDown insulation is treated with a DWR finish so the down retains its loft and superior insulating properties even in wet conditions."It adds warmth and insulation no matter where I am and it looks pretty polished too, whether I'm high up in the mountains or I'm in town."Melissa Arnot, Eddie Bauer Alpine Guide