Big Agnes Greystone 0 Sleeping Bag

Stay toasty in the backcountry with this down-filled Big Agnes 0°F sleeping bag. It's ideal for backpacking but versatile enough for couch surfing. The 650-fill-power down is light and packable.

Temperature ratings are intended as a guideline to help you compare products, rather than a guarantee of warmth, since many different factors contribute to your comfort while you sleep. Backpacking bags are typically rated for temperature according to an independent testing protocol—currently International Organization for Standardization (ISO) 23537, though some older items followed European Norm (EN) 13537. Testing is based on a person wearing one base layer and a pair of socks, sleeping on an insulated surface with a minimum R-value of 5.38.

Each bag then gets 2 ratings: the Comfort rating is the lowest temperature at which the bag will keep the average "cold sleeper" comfortable, and the Lower Limit rating is the lowest temperature at which the bag will keep the average "warm sleeper" comfortable. Some brands determine their own temperature rating by aligning to the Comfort rating for women’s bags, to the Lower Limit rating for men’s bags, or somewhere in the middle for nongendered bags.

• All-gender Greystone bags deliver technical, lightweight performance with high thermal value, compressibility and comfort—they're designed to excel on and off the trail
• Insulated with 650-fill-power Downtek™ PFC-free down; includes a water-resistant coating to keep you dry
• Baffle construction for efficient heat distribution
• Traditional mummy shape allows for light weight and increased body heat retention
• Contoured hood follows the shape of your head for a more comfortable fit
• Oversize no-draft collar and no-draft zipper to keep the cold out
• Low-profile cordlock lets you uncinch the hood with one hand
• Cinch the insulated tube along the upper hood opening to seal out drafts
• 2-way zipper and zipper garage are positioned on sleeper's left side of the bag
• 65 in. (165 cm) YKK #5 antisnag locking zipper for a smooth, quick zip
• Mate together Big Agnes left-zip (all-gender) with right-zip (women's) bags to share warmth with your tent mate
• Storage sack and stuff sack included
• Compressed dimensions: Regular: 10 x 10 in.; Long: 10 x 10.5 in.