These unique tube socks use a patented continuous filament conductive fiber (silver coated nylon, 12% silver by wt; no chemical finishes) to create unmatched stretch comfort and excellent conductivity. This advanced technology provides a whopping 633 ohm per 50 cm uniform resistivity (per AATCC#84-1987) in a washable and durable lightweight fabric. Excellent E-field shielding for your feet, good RF shielding too. Can be used to dissipate static from the body (or body voltage) onto an Earthed or conductive surface. Dairy farmers have successfully used these socks, connected to each other up the pant leg by a simple ground cord, to shunt uncomfortable and potentially dangerous ground current (stray voltage) away from their bodies. Gray. Available in 2 sizes. Made in USA.