Castelli Fatto 12 Socks

Castelli Fatto 12 Socks. This is a thin sock that performs like a thick winter sock. Made from a mixture of Primaloft and polypropylene yarns that are woven into a terry cloth construction, Castelli's Fatto socks keep feet extra warm in cold, wintry weather. In fact, they protect feet from temperatures as low as 20C 68 F, but can still easily roll up for storage or travel.