You know it's getting cold outside when you can see your breath hanging in the air. The ATMOSPHERE is the lightest down jacket we make, with a premium quality duck down fill that will keep you warm in sub-zero temperatures. The STORMLOCK shell boosts the insulation performance by blocking the cold winter wind, while light showers simply bead up and run off the surface of the fabric. The ATMOSPHERE is also extremely breathable, so it's ideal for all kinds of winter sports, from X/C and downhill skiing to snowshoeing. And if you get too warm, simply stash it in the stuff sack and drop it in your pack.