What truly makes the men\'s Burton [ak] LZ Down Jacket a more powerful puffy is that it\'s the only Burton down parka wrapped in fully waterproof and highly breathable GORE-TEX seam taped GORE-TEX two-layer fabric. On the inside, responsibly sourced 800 RSD goose down fill cranks up the heat while keeping overall weight to a minimum. Comfort-focused features include an articulated [ak] fit for a full range of motion, a StormForm attached Contour hood, ample venting, a facemask-friendly neck gasket collar, and powder gasket cuffs. It\'s all backed by a lifetime warranty.