This is some very warm wool underwear. It sells for about $60.00 for a top. It is loop weaved and is the stuff those guys wear who trap crabs in the artic. I got a top to wear and it is incredible warm. They say you can wear the same top for over a week because it doesn't pick up odor. Check it out on the web. I have the 200gr, they have 400gr , 600gr, and 800gr, which is like a jacket. Fox Ridge Outfitters seems to have a good price. That is if there is such a thing as good at these levels. King of the Mountain reccomends wearing this under their products. Just an interesting choice. Buckfever