The Outgo Ultra-Compact COOLMAXA(R) Sleep Sack is a lightweight and compact sleep sack and sleeping bag liner. The COOLMAX performance fabric features an effective fiber-based moisture management system, which can move perspiration away from the body and through the fabric, where it can evaporate quickly, allowing for a more comfortable night's sleep. Featuring a soft and comfortable feel, this mummy-style sleep sack weighs less than 10oz. and packs easily into the 6" x 4" vented stuff sack. Available in blue or green. Care: Machine wash cold. Tumble dry low.