Leave the tent, flick on the headlamp, swing the tools, tag the summit and return - for every moment of an alpine mission, the Nano-Air delivers a breakthrough in active insulation. Put it on and leave it on through high-output, stop-and-go alpine missions - its exclusive, stretchy and highly breathable fabric package integrates the qualities of fleece, soft shell and puffy by combining a plain-weave liner, warm-when-wet FullRange insulation, and a lightweight-yet-durable, weather-shedding shell with DWR (durable water repellent) finish. The jacket's incredibly soft, supple feel and full mechanical stretch allows for a close, athletic fit over baselayers and an uninhibited range of motion. At brew stops or in frigid conditions, pull on a lightweight shell and the Nano-Air's thermal properties skyrocket. The left-chest pocket and two above-harness handwarmer pockets all close with trim, low-bulk zippers. The center-front zipper has a storm flap and zipper garage, while stretch binding at the cuffs and a dual-adjustable drawcord hem seal in warmth.