This is the "Defence 4" made by Carinthia in Austria...
A well known bag and it is used by lots of Forces in Europe -
check it out on youtube...
I used both bags down to 16 F in a tent 5 days in November and down to the mid 20's for 3 days this February without a tent. The bags worked great together. I slept in my thermals without socks and the bag combo kept my feet warm, I was not expecting that. If you want to keep some items you don't want to expose to those low temeratures you may need the longer bag as it is a snug fit with the regular size. I usually hike with the Ultra Light bag; however, I just had to get out during this pademic and both bags work great down to 16 F in my experience.
Extremely well made product.
Great zipper! It doesn't snag at all.
Bag is awesome. No problems in the 20's. I've taken it out to 16 F, and the warmth is decent, but I will need a sweater if it gets any colder.
I give this bag 4.5 stars. I have done 5 nights under 20 F now. This is a good bag.
I will be cold below 10 degrees, but I'm a desert rat and turn the heat on at the first hint of cool air. I'll wear my insulated clothing to bed and should be able to go to 0F with minimal discomfort. I would not go that low regularly with this bag though.
I am 5 10 and wish I got the tall version as I dont have enough room to shove clothes, water, and fuel cans into the foot of the bag to prevent them from freezing.
Only other complaint is the bag is little heavy; but there is no way to get around this with synthetic materials. Buy down and freeze to death on a wet night if you want a lighter bag.
I highly reccomend this bag and expect this bag to last at least a decade.