The lightest weight bag ever built, the Mountain Hardware Mtn Speed 32 uses the lightest weight materials available. Insulated with 850 down, and constructed with 7D x 10D fabric, they have only included the essentials in this minimalist bag. Premium, 850- fill down provides outstanding, lightweight warmth with a 5 inch baffle spacing that gives maximum loft. Lightweight half length #3 zipper for easy entry, but sized to be light weight. Five chamber hood design maintains even loft around the hear for consistient warmth. The weight of this high-performance bag has to be felt to be believed.