Mountain Hardwear Unisex Ultralamina 32 Sleeping Bag LEFTnotruc(Engineered to be lightest and warmest synthetic bag available,500) Performance mummy cut is snug, reducing girth, weight, and bulk and maximizing thermal efficiency Proprietary welded Lamina construction enhances loft and eliminates cold spots Ultralight shell is soft and highly wind resistant Thermal.Q insulation has outstanding compressibility and maintains excellent loft