Darn Tough OTC Heavyweight Sock - Full Cushion | Merino Wool Over-the-Calf Socks

Extreme Cold Weather OTC Tactical Boot Socks – Full Cushion Maximum Warmth. Rugged Terrain Ready. Mission Approved. When the temp drops and the terrain gets unforgiving, this is the sock you reach for. The Extreme Cold Weather/Mountaineering Over-the-Calf (OTC) Sock is the warmest and tallest sock in the tactical lineup. Built for freezing environments and high-exertion missions, these heavyweight Merino wool socks deliver full-cushion comfort, reinforced durability, and zero quit. Whether you're on duty, training in the elements, or deployed into the mountains, these over-the-calf tactical boot socks are engineered to work as hard as you do. Berry Compliant, USAF Safe to Fly Certified, and NAVAIR SOA Approved, they meet strict military standards—while still being soft, breathable, and built to outlast the mission. Why We Love It: These are not your standard-issue socks. They’re Made in the USA from Merino wool that wicks moisture, regulates temperature, and holds heat even when wet. T