Whether we're posted up by the campfire, enjoying our seventh s'more of the evening, or cruising up one of Castle Rock's famed routes, the Nano Puff is always along for the ride and provides classic style and lightweight warmth. This classic midlayer boasts a tenacious exterior thanks to the recycled polyester shell and lining, which when combined keeps wind out and warmth in, while the fabric is also treated to prevent light precipitation from getting the best of your time spent outside.