Comfort starts from the inside, out. Naturally insulating, moisture wicking and antimicrobial - Merino Wool and performance yarns wrap your feet in cushioned comfort. 38% Merino content, the most in the sock line-up, boosts the Boot Sock Thermal insulating power for the coldest, longest days on deck. High-power instep elastic locks in a blister-free fit. Nylon reinforcement yarns at heel and toe boost durability. We&&';;re so confident in our USA made, sustainably sourced socks that we&&';;re putting a lifetime warranty behind them. If your socks fail, we&';ll replace them, no questions asked. Product Features: Natural Wool Insulation Moisture Wicking Anti-Microbial High-power instep elastic reduces blister onset Nylon-yarn reinforced heel & toe sections maintain durability Lifetime Sock Warranty - We&';re so confident in our USA made, sustainably sourced socks that we&';re putting a lifetime warranty behind them. If your socks fail, we&';ll replace them, no questions asked.