The synthetic REI Zen 10 bag balances price and performance. Light, compressible insulation and unique construction work together to maximize warmth when the temperature dips. REI-exclusive Z-Baffle construction combines 2 insulations that together maximize heat retention far more efficiently than a single insulation. Synthetic polyester fill retains insulating properties even when wet. Equally distributed insulation accommodates the multi-position sleeper mummy shape is thermally efficient, yet roomy enough from shoulder to knee to ensure sleeping comfort. Hood, insulated muffler, roomy footbox and full-length zipper draft tube with ground-level seams keep heat in and cold out. External chest pocket keeps essentials-headlamp, watch, glasses-right at hand and easy to find in the dark. Special pocket can be stuffed to make a pillow that stays in place no need for a pillow to take up valuable space in your backpack. Pad loops provide attachment points to keep your sleeping bag and pad together, so you neednt worry about rolling onto the cold ground straps sold separately. Differentiated drawcords allow quick identification, even in the dark, so neck or hood adjustments are a cinch Ripstop nylon shell and soft taffeta lining offer durability with abrasion- and tear-resistance for years of use. European Norm EN comfort rating allows direct comparison with comfort ratings of any other EN-rated bag. Nylon stuff sack and cotton storage bag included.