Nemo Sonic 0-Degree Down Mummy Bag AWARD-WINNING DESIGN - The Sonic can take you from basecamp to summit thanks to adjustable Thermo Gills that extend your comfort range by 20 degrees or more; Rated to 0F / -18C SLEEP LIKE A HUMAN - Unlike traditional mummy bags that restrict movement, the Sonic's stretch construction at the knees adds enough volume to accommodate side sleeping SUPERIOR WARMTH - An oversized draft collar traps body heat and an offset zipper creates a thermally efficient seal; Waterproof yet breathable footbox keeps feet warm till morning CERTIFIED RESPONSIBLE DOWN - Insulated with 100% RDS Certified down, which is traceable to ensure humane treatment through the entire supply chain TECHNICAL SPECS - Weighs 2 lb 10 oz (1.2 kg) with a compressed volume of 7.7 L; Nylon Ripstop with water-resistant DWR; Fits men or women up to 6 ft tall; Left zipper