From casual strolls around town to the most adventurous mountaineering endeavors, this jacket keeps us warm through all of it. The 800-fill down insulation ensures high-quality, dependable warmth that's also lightweight and super packable, while the Pertex Quantum body adds windproof and water-repellent protection from the elements. This fabric also uses Pertex Y Fuse technology to increase the downproofing of the jacket and help water bead off more effectively.