With an exceptional warmth-to-weight ratio, the Swisswool Piz Duan Vest is our go-to choice for mountain adventures that call for full-ranging mobility and warmth without any extra bulk slowing us down. The breathable, wind- and water-resistant face fabric helps us comfortably cut through the elements, while the insulating Swisswool lining keeps our core warm as we take in the view from the summit.