You'll be hard-pressed to find something better than down in terms of warmth, light weight and compressibility. The North Face Thunder Jacket wraps 800 fill down in durable nylon ripstop treated with a DWR (durable water repellent) finish for a super warm and weather resistant puffy. This ultra-lightweight, high-power down jacket packs into its own pocket and takes up almost no space inside your pack, making the Thunder ideal for both around town cruising and those cold backcountry expeditions.