SCK is a ski sock with a Norwegian pattern and is made of 85% MERINO. These socks are very warm and have been specially designed for harsh weather conditions. Maximum comfort, protection and foot care is ensured by a warm and soft two-layer plush in combination with a three-layer plush fitted on the sole, heel and instep. Elastic is fitted around the instep and shin area. It also creates air pockets which greatly improve the thermal insulation properties of the sock. The upper hem is wide and extremely flexible and pleasantly hugs the shin and calf without creating an unpleasant grip.What size do I need?