This sleeping bag is extremely comfortable and can go very cold, even colder than rated if you are dressed in layers. The zipper is nice and has only gotten stuck once out of dozens of uses, and when you're inside of the bag you can tighten the hood, and tighten the bag around your body to keep heat in. You can also easily adjust the zipper from inside or outside of the bag. It compacts very small and light. I used this hammock camping on the shore of Lake Superior in the U.P. in March on a very windy night, it got down to 11 F. Windchill was much colder, but I stayed warm. I am a warm sleeper though, and have a hammock setup with an underquilt. This bag is perfect for me. Great value for the price