The ultra-packable women's Burton [ak] Helium Insulator Jacket regulates core temperatures via low-profile insulation, while maintaining a tailored women's silhouette that slides easily under a shell. Integrated PrimaLoft panels harness military-grade insulation to provide maximum comfort and ultra-breathable warmth where your body demands it most. Buttery soft and water-repellent fabric reduces layering friction, while super breathable stretch underarm and side panels dump today's moisture, yesterday. * Designed For Ultimate Layering Performance * Engineered Insulation at Side Body with Breathable Underarm Paneling * Mapped with stretch Thermacore Insulation (60G Throughout) - Developed for superior warmth-to-weight, Thermacor cranks the heat without limiting mobility. * Slim Fit, Interior Stash Pockets and Zippered Handwarmer Pockets * bluesign approved for a reduced impact on both people and the environment NWOT