Small: Women 5 - 8, Medium: Men 6 - 9 / Women 8 -11, Large: Men 9 - 12 LewisN. Clark Flight Socks provide graduated leg compression and support to improveblood circulation, prevent tired, swollen legs on long flights. They aid inthe prevention of Deep Vein Thrombosis (DVT). DVT is a condition in which ablood clot forms in a vein that is deep inside the body, and mainly affectsthe large veins in the lower leg and thigh.Intended for use with healthylegs.. Provides graduated leg compression and support to improve bloodcirculation and aid in the prevention of Deep VeinThrombosis (DVT). Helpsprevent tired, swollen legs on long journeys. Includes one pair calf-lengthsocks available in small, medium and large. 95% nylon, 5% spandex. Intendedfor use with healthy legs. Small(S Women 5 “ 8 Medium(M) Men 6 “ 9 / Women 8 “11 Large(L) Men 9 “ 12