Great comfort and protection while on the job. The U.S. Postal Service gives Thorlos navy crew socks with Postal Blue stripes a stamp of approval. The flat knit instep of these postal work socks offers efficient moisture evaporation and a better overall fit. The lightweight padding in arch and midweight padding at the ball and heel protect against shock, impact, blisters, and abrasions. The Acrylic construction of these black crew socks keeps feet drier on the inside and the reinforcing nylon knit on the outside, provides outstanding durability. These durable USPS uniform socks are ideal for Letter Carriers and Postal employees on their feet for a good part of the day.