The Performance Series tetrasock is engineered to separate your toes with a CoolMax® moisture wicking lining and a resistant nylon outer shell built with Lycra® fibres, to create a thin, anti-friction membrane that is both lightweight and breathable. Seamless in construction, the tetrasock forms to every contour of your feet. This allows for true rectriction free movement from your heel to five toes, encourages healthy circulation, and eliminates skin on skin contact between your toes to prevent blistering.