Leader Crew Length Diabetic Socks Seamless Toe Large, Black. Leader Diabetic Crew Socks in black have advanced air channels for ventilation. The socks enhance circulation, keep feet dry, and reduce the chance of a foot injury. Its non-abrasive toe construction is seamless, keeping the wearer comfortable. These high-cut crew socks are a size large and black. People with diabetes are more likely to have foot problems because diabetes can damage nerves and decrease blood flow to the feet.