The REI Zephyr sleeping bag's 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
Mummy shape is thermally efficient, yet roomy enough from shoulder to knee to ensure sleeping comfort
Hood, insulated muffler and full-length zipper draft tube keep heat in and cold out
Exterior chest pocket is great for stowing small necessities such as your watch, eyeglasses and lip balm, alleviating middle-of-the-night fumbling
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 needn't worry about rolling onto the cold ground (straps sold separately)
Differentiated drawcords allow quick identification, even in the dark—neck and hood adjustments are a cinch!
Ripstop nylon shell offers durability with abrasion- and tear-resistance for years of use
Nylon stuff sack and cotton storage bag included
Ever notice how most sleeping bags are made out of 1 type of insulation? When you sleep, you lose heat in different ways. While convective heat loss is generally regulated by loft, radiation (in the infrared range) will be best reflected by fibers whose size closely matches the wavelength of your emitted radiation. With this in mind, we've combined a burly, durable, lofty continuous filament insulation that's good at blocking air movement with a soft, fine, thermally bonded fiber optimized to reflect back your radiant heat. This creates a warmer, softer, loftier and more compressible bag than single insulation bags.