The Ski+ Medium OTC Mountain Contour Sock uses an anatomical, seamless construction with Achilles support to stay in place through a full resort or backcountry ski day. A merino wool blend regulates warmth in the cold without overheating, and a seamless toe cuts down on bulk and friction inside the boot. Medium cushioning and an over the calf height round out a sock built for real days on snow, not just the lift line. What Our Gearhead(R) Experts Are Saying:"I've skied a full resort day in these without a single mid-run boot adjustment. The Achilles support and soft cuff keep the sock exactly where it started, even after hours of hard turns."