FITS Wader OTC Socks are over the calf socks that keep your feet warm all day. Ideal for those ice-cold waters. These socks are designed with cushioning that surrounds your foot, ankle, and calf. Heel Lock for heel security, helps reduce chances of a blister when used with correct fitting bootsDynamic Toe Cup - Forms to the shape of your feetNylon reinforced exterior69% Super-fine merino wool24% nylon4% polyester3% LycraDouble welted top that keeps socks from slipping downMerino Wool Fabric Tech: Moisture Wicking and Quick DryingBreathable and Temperature RegulatingOdor Resistant and AntimicrobialAnti-itchFlame Resistant