The Peak Performance Helium Down Hybrid Hood Jacket, thanks to its stretch side panels, is incredibly comfortable and allows for full range of motion. It's perfect as a second layer under a shell or down jacket, but also great to wear on its own. It's windproof, and thanks to its DWR-treated nylon shell fabric, it protects against light precipitation. It packs down to a very small size. Plus, it's insulated with premium 90/10 duck down and feathers, responsibly sourced and compliant with the "Track My Down®" program, guaranteeing warmth.