Go head-to-head with Old Man Winter with this lightweight, yet high-performance down jacket. The Sister Brook is Interchange-compatible so you can adapt to changing conditions even while the jacket's funnel neck design, thermal-reflective lining, and 700-fill power down insulation keep you plenty warm on its own. It's also both ruggedly durable (including a 100% nylon Mini Rip-Stop shell) and highly portable (packable into its own custom stuff sack).