Lorpen Expedition Polartex Knee length Sock id ideal in extreme weather conditions. The sock is anatomically designed and comprises a three layer construction. A inner layer on the sole of the foot is made from Polartex Powderdry and has antibacterial properties.The sock has a full heavy cushioning and added Polartex Powerstretch gives added comfort and stretch. The sock comes up over the calf to the knee and is dark grey in color. Please note this sock tends to fit small so please allow for this in choosing your size. The sock comes in sizes Medium, Large, ExLarge.