![Shot of two models wearing 1056 Men's Bolt Micro Crew Ultra-Lightweight Running Sock in black colorway and 1063 Women's Relay Micro Crew Ultra-Lightweight Running Sock in Mint colorway running up brightly painted steps](https://cdn.statically.io/img/darntough.com/cdn/shop/collections/All_Ultra-Lightweight_PLP_1920x.jpg?v=1704977843)
Ultra-Lightweight
The ultimate like-it’s-not-even-there fit. Ultralight socks are knit from ultra-lightweight yarns, for our thinnest socks with the lowest in-shoe profile. With ultralight merino, you get all the benefits of wool socks — breathable, thermoregulating, odor-resistant — in a sock so low profile, you might forget it's there. These are socks you can run in for miles or ski in all day, durable and comfortable.