When you're high up on the mountain, the last thing you want to worry about is your feet. Wear the Smartwool Mountaineering Extra Heavy Crew Sock, and focus all of your energy on bagging that summit. This crew-length sock utilizes Smartwool's wool-on-wool technology for maximum extra-heavy cushioning and durability. A flat-knit toe seam helps to avoid irritation inside your boot, and Smartwool's fit system gives added arch and ankle support. The natural anti-odor properties of merino wool fend off funky odors from interfering with your expedition.