Weather protection also for winter: lightweight and small packable bivy sack made of waterproof, bluesign certified material. Offers good weather protection thanks to a body-hugging mummy cut, hood and drawcord. This bivy sack can be worn over the sleeping bag (protection from snow, rain and wind) or as a VB liner inside the sleeping bag on winter tours. This prevents the dew point from moving into the sleeping bag at low temperatures and the down from losing its insulating capacity.