This 4-season sleeping bag is compact and lightweight, making it the perfect backpacking sleeping bag. It features a water-resistant, lightweight, and durable 20D nylon shell and 300D microfiber lining for soft-touch comfort. It's filled with synthetic polyester filaments that keep you warm even when wet. The mummy-style hood can cinch in around your head for additional warmth and keeps your pillow clean. Its durable shell will stand up to years of rigorous adventure. It's a warm, comfortable sleeping bag that's soft to the touch, but don't take our word for it - read our history and the reviews! Woods invented the original down 'sleeping robe' in 1906.