I was not sure how these socks differed from the Ultraz version when I bought them, but after using both of them I now understand. This sock is thinner than the Ultraz and does not have the extra material towards the toe. If your shoes are tight then these would be the better sock because once you wear socks that are too thick for your shoes, you will restrict blood flow in your feet and hello cold feet.
This sock is a bit taller than the Ultraz as well. I really like this pair and wear them more often than the Ultraz because I do not need the level of warmth most of the time and I like the thinner socks.
These are comfortable when temps are in the 30s and 40s. No complaints.
