The ideal, versatile sock to be worn all year round, unless you’re working outside in extreme heat or extreme cold, the Ultra is a good general choice. This sock has extra conductive properties, ESD.* Available in sizes 35 - 53. 46% COTTON 34% POLYESTER (COOLMAX) 12% POLYAMIDE 6% POLYAMIDE (CORDURA) 2% ELASTOMER (LYCRA) 4-channel Coolmax® transports moisture instantly - step by step. Cordura® reinforces and strengthens the socks, extending their lifespan. Different styles for different seasons, levels of activity. Sanitized kills bacteria and odour. Quick drying - in and out of the shoe. Wear with EMMA shoes for the driest, condurefreshest feet. THe Hydro-Dry® working is available in sizes 35 - 53.