An arch brace holds the sock in place and adds additional support, while a flat-knit toe seam keeps you comfortable throughout the day. Perfect for moderate hiking or aggressive walking. Men's Sizing: Small (Men's Shoe 3-5.5) - Medium (Men's Shoe 6-8.5) - Large (Men's Shoe 9-11.5) - XL (Men's Shoe 12-14.5)