Darn Tough T4050 Tactical OTC Heavyweight With Full CushionThe warmest and tallest sock in the line, the Extreme Cold Weather Mountaineering over the calf sock is designed for extreme climate on rugged terrain. Featuring full terry loop cushioning throughout for maximum warmth. Elastic support at arch. Reinforced heel and toe for increased durability. USAF Safe to Fly Certified and NAVAIR SOA Approved Height: OTC Weight: Heavyweight Pair with: Military combat boots, tactical boots, ocp boots Style Number: