I think this is what these bags are-

INTERMEDIATE COLD WEATHER BAG FEATURES: Temperature to -10degrees, from from cold spots, insulation does not migrate in the bag, anatomically designed foot box contains twice the insulation as the bag, sewn-in, quilted chest collar prevents air drafts up and down through the hood, hood adjusts for heat retention; includes nylon drawcord and barrel lock. Color Black

Its a Mummy style, zipper and snaps. I think made from some kind of poly- not cotton. I think are are the newer style. They are used- but look like new.

$40 ea