Ultra half crew is a thin, yet warm wool sock for both hiking and everyday use. Ultra is soft and comfortable with added re-enforcements on heel and toe area. Wool sock has unique temperature regulation and moisture wicking properties. Wool is naturally anti-bakterial. Wool socks may be used several times in a row without washing, and is more odor resistant compared to synthetic socks. Suitable for everyday use. This model has a bit lower leg height than the classical Ultra sock.