The Icebreaker Ski+ Medium OTC Mountain Contour Sock is a merino wool blend sock built for full days inside a ski boot. The wool blend regulates temperature as conditions shift from the lift line to a sweaty bootpack, while targeted cushioning and an anatomical shape wrap the foot for a precise, supportive fit through the calf. What Our Gearhead(R) Experts Are Saying:"The reinforced heel and toe are what I notice by the end of a resort day. My boots don't create hot spots the way they do with a thinner sock, and the cuff stays put through every buckle adjustment."