The North Face Women's Furnace 20 Degree Sleeping Bag is revised to be lighter and roomier than ever for a more comfortable camping experience. Maintaining its three-season versatility, the Furnace 20 Degree Down Bag retains lofty warmth on cold evenings under the stars. Since it's predominately filled with compressible down, the Furnace 20 compactly packs into the included stuff sack for easier carrying. It's stuffed with 600-fill ProDown for fiery heat retention when temperatures drop below freezing overnight. Repelling humidity and outside moisture, ProDown uses a hydrophobic down treatment that maintains its lofting power in wet environments. Complementing the ProDown, HeatSeeker insulation is placed along the bottom panel to eliminate cold spots. This synthetic insulation features anti-compression properties to maintain its lofting warmth under your body weight where down would normally falter.