Desert Fox Bilayer Heat Retaining Single Outdoor Camping And Travel Mummy Sleeping Bag Sack Four Seasons General Size: 78.5"31.5"*19.5" / Filling material: hollow cotton. 210T polyester fabric is ripstop and waterproof. Hollow cotton fillings and extra collar leads to heat retaining. Innovative 3D stereoscopic tail design can free your feet to be more comfortable. Special inner storage pocket can used to carry the valuables. Gorgeous zipper with double sliders is more convenient.