The SmartWool Outdoor Sport Medium Crew Sock is perfect for long day hikes or backpacking trips when you need just a little more cushioning. The 4-Degree Fit System provides added support around the ankle, arch, and all along the instep. WOW Technology in high-density impact zones reduces shock and abrasions for increased performance. Strategic mesh ventilation zones yield maximum breathability where you need it most. The reinforced heel and toe add extra durability to ensure long-lasting wear. The 1 x 1 double-ribbed cuff and flat-knit toe seam help keep feet comfortable all throughout the day. This medium, full-cushioned crew sock is knit from a rugged blend of 81% Merino wool, 18% nylon, and 1% elastane fabric. Made in the USA.