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Sea to Summit says:
The Silk-Cotton Blend Travel sleeping bag liner is a luxurious and practical option employing two natural fibers blended together for premium comfort and performance. This is ideal for any travel adventure around the globe, and if you're not sure about your hostel sheets, then the Silk-Cotton Blend Sleeping Bag liner is the perfect solution. If you're backpacking it'll keep your sleeping bag clean and it's machine washable. This lightweight, compact and luxurious liner is super soft on skin and is packaged in a handy zippered pouch.