Marmot Trestles 15 Cold-Weather Mummy Sleeping Bag, 15-Degree Rating Synthetic Mummy-style 15-degree sleeping bag for backpacking, camping, and other outdoor activities Maximum warmth/durable SpiraFil high-loft insulation; EN rated as comfortable for men at a lower limit of approximately 15 degrees Fahrenheit Anatomically shaped footbox for more wiggle room and less heat buildup Regular: Weight: 4 lbs., 8 oz.; pack volume: 762.8ci (12.5 liters); interior length: 75"; 70D 100% polyester, 2.2 oz/yd; 70D 100% embossed polyester, 2.2 oz/yd Long: Weight: 4 lbs., 12.6 oz.; pack volume: 860.4ci (14.1 liters); interior length: 82"; 70D 100% polyester, 2.2 oz/yd; 70D 100% embossed polyester, 2.2 oz/yd