The wool-blend fabric in our Keyport Wool Crewneck is inspired by a vintage extra-warm wool union suit. It’s highly unlikely that a warmer baselayer exists, though most would wear this thermal as a light sweater. The 55% wool/45% polyester blend is highly durable with a coarse, rustic feel. The wool insulates dry or wet, and excels at wicking moisture away from the body. Wide rib-knit cuffs maintain their shape over years of cold-weather wear. Wide rib-knit cuffs keep sleeves where they belong when layering. Rib-knit collar.