Quality, Comfort and Durability. THE STERLING PROSTHETIC SOCK was first developed in 1921. Since that time, the finest materials and outstanding workmanship have been combined with the most innovative technologies available to produce premier prosthetic socks. Standard features include: a reinforced toe, a more rounded toe and the absence of large open stitches. All Sterling socks are finished with a color-coded thread at the top hem that enables patients to identify the ply of the sock after repeated laundering.