The Mountain Equipment Classic 1000 is a very warm down sleeping bag filled with pure duck down. The sleeping bag is very packable and relatively light. It is great for trekking and adventurous travel at higher altitude where the temperature drops well below freezing. The sleeping bag has a mountain fit, which is both spacious and thermally efficient. The 2 baffle anatomically shaped footbox is particularly roomy. The outer shell is made of nylon, which is soft, tearproof and down proof. The material is both extremely breathable and windproof as well. The interior is equipped with Supersoft 30, a very breathable and robust fabric that is very soft and lightweight. The sleeping bag comes with a waterproof stuff sack as well as a storage cube. With the Mountain Equipment Classic 1000 down sleeping bag, you'll have a reliable and thermally efficient partner for sub-zero temperatures!