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 traditional style. When insulation material
is compressed under your body, it loses most of its ability to insulate. Big
Agnes eliminates the unnecessary bottom insulation and replaces it with
a sleeve to accommodate the pad which provides the insulation. This
design provides a secure foundation and keeps you on the pad all night.
Benefits of the system include: weight savings, reduced packed size,
increased girth and comfort and the ability to roll and twist without
rolling off your pad or waking to the feel of a zipper across your face.