Fifteen years after we introduced our R1® fabric, it remains a favorite the world over for good reason: it stretches, breathes, wicks and warms with ultimate efficiency. The full-zip iteration only enhances its range, whether worn as a midlayer or a lightweight jacket. The finely tuned high/low interior grid polyester fabric (Polartec® Power Grid®) remains light, breathable and exclusive to Patagonia. With its technical fit and durable fabric, it squashes down to practically nothing in your pack. A soft, kissing-welt zipper garage at the chin gives next-to-skin comfort, the simple cuffs keep a low profile, two zippered handwarmer pockets sit above the harness line, and offset shoulder seams steer clear of pack straps. Polygiene® permanent odor control enhances partner relations.