The technical midlayer that offers breathable warmth without the bulk. Once you've tried it, you'll never forget to pack the Patagonia R1. Its unique texture helps keep you warm when you're not moving, but also wicks moisture and maintains breathability during high-exertion ascents. With minimal bulk, it can easily fit under a harness or stuff down into your pack when you're not using it, and the slim-fit hood layers easily underneath a helmet or jacket hood. It's the perfect companion for any mountain adventure.