What if you only needed one sleeping bag for every season? 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-wide. 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. Use this bag in any of the following arrangements for your desired temperature rating: *Sleep in the inner bag for +60°F/+16°C *Sleep in the outer bag for +30°F/-1°C *Sleep on top of the inner bag for one layer above and three below for +20°F/-7°C *Sleep inside both bags for two layers above and two below for 0°F/-18°C *Use a sleeping pad and sleep under the inner bag for three layers above and one below for -10°F/-23°C For double-wide arrangements, unzip the bags separate of each other and open them fully. Zip the inner bag to the outer bag in a double-wide configuration: *Couples can sleep under the inner bag for +50°F/+10°C *or the outer bag for +45°F/+7°C Like all TETON Sports sleeping bags. Zipper baffle on both inner and outer bag to reduce heat loss, Shoulder baffle with drawstring and barrel-lock on inner bag.