Lightweight, summer style athletic socks made by the foot freaks at DeFeet. They specialize in cycling socks so we don’t have to talk to those nerds. I am writing this wearing the socks, one of two pairs I grabbed because they look so good I need them twice a week. I recommend you do the same.nMedium Sox fit a US Men’s Shoe size 7-9 Women’s 8.5-10.5nnLarge Sox fit a US Men’s Shoe size 9.5 – 11.5 Wommen’s 11-13