The Big Agnes Women's Lulu Sleeping Bag offers warmth to 15 degrees and proctection from moisture with Climasheild HL continuous-filament insulation. The Lulu is designed just for women and includes the company's popular integrated pad sleeve system, synthetic insulation and room to move around at night. The Big Agnes system is different than the traditional sleeping abg on top of a sleeping pad. Instead, they unite the two. With Big Agnes, the pad slides into an integrated sleeve on the bottom of the bag, and the top two-thirds of the bag is insulated in the tradition style. When insulation material is compressed under the body, it loses most of it's ability to insulat. They eliminate the unnecessary bottom insulation and replaced it with a sleeve to accommodate the pad which provides insulation.