The Kelty Callisto 35 is a mid-summer nights dream, spacious yet soft and cozy to snuggle up in. The Callisto can be fully unzipped to create a blanket or zipped together with another with another rectangular Kelty bag to form a double. The Kelty Callisto 35 degree sleeping bag features two-layer off-set quilt construction and differential cut to maximize loft and warmth. The two-way, locking blanket zipper allows the bag to be opened completely and used as a blanket and has a draft tube with anti-snag design.