The 5.11 Tactical Merino OTC Boot Sock is made from premium Merino wool along with copper threads. These socks complement all of 5.11's footwear, and the NanoGLIDE technology ensures comfort in any environment. The heel, sole, and toe have been reinforced for enhanced performance and durability. These socks are moisture-wicking and have an odor-controlling liner that fights bacteria. The Merino OTC Boot Sock provides superior comfort, agility, and traction and are ideal for any mission. The over the calf length is ideal for wear with any boot or other tactical footwear so you'll stay warm, dry, and ready for whatever the day throws at you. Lastly, there is a Tab-top cuff and these socks are proudly made in the USA.