Untracked lines call. Head for ridgetop in the men's Burton [ak] Helium Stretch Insulated Jacket. The lightweight jacket delivers breathable warmth in a pack-friendly design for backcountry missions. Its stretch fabric lets you move naturally while keeping it light and breathable. It's the midweight layer you can wear on the uptrack when it's cool and breezy or under your shell to stay warm on the descent. When the sun shines and the temps rise, it packs into its own pocket for easy stowing.