The Kelty Callisto 30 Sleeping Bag is a synthetic sleeping bag for your relaxed summer life. CloudLoft Insulation provides warmth in temps down to 30°F, so bring on the summer heat and sleep under the stars. Whether you're in a tent or not, the rectangular shape provides plenty of space to wiggle around in. Or open it up and lay it flat, blanket-style. Yeah, that means it's ready for fireworks or snuggles with your sweetie.