Sleeping Bag Shells: The outer fabric, which is made of durable polyester or nylon, has a durable water repellent (DWR) finish to protect the insulation inside the shell from moisture. Inside the bag, you will find materials with a soft and warm texture.
Sleeping Bag Hood: A tight hood can make a bag much warmer, so you are more likely to find hoods in bags with lower temperature ratings.
Zipper Features: Getting a bag with more than one zipper slider makes it easy to adjust the ventilation. In addition, some bags prevent the zipper from snagging by protecting the zipper with a protector along its entire length; others address the problem with a cover for the zipper itself.
Stash Pocket: Some bags offer a handy zippered stash for things like a watch or lip balm.