Our legendary synthetic-insulated, seamless construction Lamina(TM) family of sleeping bags are back with new shell fabric and Temperlite(TM) insulation that delivers the same workhorse performance in a dramatically lighter package, without sacrificing durability. Unique Lamina(TM) construction maximizes the loft of your insulation; eliminates cold spots; and thermally maps insulation to concentrate warmth where you need it most.