My backpacking buddy now calls me the official "Sierra Madre Advocate" as I sported my new DelSur on a bushwacking hike in the north Georgia mountains en route to the Chatooga River. It is the perfect combination of core insulation and breathability. As the temperature dropped into the 20's that night, I climbed into my SM NINOX flat lay hammock, complete with SM NINOX fly and SM underquilt while still sporting my DelSur. The breathability of the DelSur made for a comfortable nights sleep - perhaps added by the fact that it was too cold for coyotes and bear!