Lighter than its predecessors, the Mountain Hardwear Lamina 15F Sleeping Bag is leaner and meaner this season. With a 15-degree rating, this sleeping bag is best for shoulder season camping with new Temperlite insulation reducing weight without compromising the bag's warmth. Mountain Hardwear's proprietary Lamina construction also enhances loft and eliminates cold spots with body-mapped insulation that concentrates the synthetic fill where we need it most while reducing weight and bulk everywhere else. The standard mummy shape is less bulky and more efficient than rectangular bags, keeping us warm and comfortable when the mercury dips below freezing.