The robust Slumberjack Timberjack series of sleeping bags are feature rich, and are designed for maximum comfort and warmth. For summer excursions, the Slumberjack 40 Degree TimberJack Rectangular is a great choice. With a soft-touch lining and pillow pocket, you're assured a cozy night's sleep, and the amazing value will assure you pleasant dreams.Slumberloft? synthetic insulation. Polyester ripstop shell, soft-touch polyester lining. Two-layer offset quilt construction and differential cut prevents cold spots. Anti-snag zipper protection. Draft tube along zipper keeps out cold air and prevents heat loss. Integrated pillow pocket, stuffs into its own storage pocket when not in use. Zip-together feature allows two same-size rectangular bags to be joined, making a double-wide bag for two. Stuff sack included. Regular right zip only.