It can be travel sheet, lightweight sleeping bag, travel sleep sack thanks to its good humanized size. It can be used alone as a sleeping bag for separate dirty things, or used as a liner in down sleeping bag,or as a hotel sleeping sack. Keeps you comfortable throughout the night. The sleeping bag liner is made of cotton and premium polyester with a silky texture which makes it very soft and comfortable against your skin. Unlike normal cotton, easy to crinkle. This new type of fabric no crinkle, no pilling or fade, can be used for a long time. Despite its generous size the sleeping bag liner can be folded into a practical 21x21cm (8.3x8.3") pocket when not in use. Easy to carrying and saving pace in your backpack.