What if you only needed one sleeping bag for any time of year? A sleeping bag that was rated from 60˚F down to -10˚F depending on how you arranged it. The Polara 3-in-1 has five one-person configurations and two double-wides. Simply add or remove layers to obtain your desired temperature rating. The no-snag zippers make changing out layers easy. Outer bag features include: Thermal enhancing, double-layer construction with offset stitching that works with the adjustable shoulder draft tubes and full-length zipper draft tubes to eliminate cold spots. The inner bag is made of PolarLite fleece that is anti-pilling and extra soft for maximum comfort.