The Bolt Micro Crew Ultra-Lightweight Running Sock is an ultra-lightweight, micro crew sock designed for use in all seasons. Constructed with merino wool, you are sure to feel all-day comfort thanks to its moisture wicking, fast drying, and odor resistant properties. The Bolt Micro Crew features a performance fit, meaning no slipping, bunching, or blisters will occur while you are out setting PRs on your favorite trail.