Bivy bags were originally developed as survival gear for climbers adventuring in the Alps. Over the years, many hikers have also taken an interest in them, and for ultra-endurance activities, bivy bags are a popular choice for overnight protection over a sleeping bag. This lightweight and compact bag provides an extra protective layer for your sleeping bag, helping to prevent wind from carrying away the warmth trapped inside. The fabric has a water column rating of 10,000 mm, keeping out rain. However, sleeping in a bivy during heavy rain can be, to put it mildly, a rugged experienceas moisture can't easily escape in wet conditions, you might wake up feeling a bit damp. The Rab Storm Bivi is made from durable ripstop nylon. The fabrics strength and performance make it suitable not just for emergencies but also for regular usethis could easily become a new favorite shelter for adventurous explorers. - Made from ripstop nylon, with a heavier material on the bottom and lighter o