Its a decent sock especially for the price and its made domestically. The -5 to -20 is a little optimistic. My feet are fine at 20 deg, but I do notice things are cooler. Below 0.maybe with a liner sock and insulated boot. I have better socks but they do cost at least 2x what these do and the difference between them wont change your life except for those days when hunting in the negative double digits.Update; They are good down to 5 deg, no liner uninsulated boot. Im pretty active and rarely wear insulated boots. If i was standing around these would be good for about 15 deg.