Built to handle winter temperatures down to -20° F, Kelty's Mistral -20 has ample amounts of Cloudloft synthetic insulation and features like a full baffle collar and generous anti-snap zipper draft tube to keep the heat where it belongs!Read more
Two Layer Offset Quilt Construction
By layering two or more sheets of insulation between the liner and shell of a sleeping bag, heat is easily trapped and maintained. To eliminate cold spots, one layer of fill is stitched to the liner, another layer is stitched to the shell, and then the quilt lines are offset so they do not lie on top of one another. Offset quilt construction is durable and maintains its shape and structure after many uses.
Advantages of synthetic fill are its ability to maintain insulating properties when wet and that it has less required maintenance than down, as well as having the potential to be recycled.