Dr. Comfort diabetic extra roomy socks are designed for people with larger calves. The Dr. Comfort extra roomy sock can fit a calf up to 24 inches in diameter. Their smooth-seam construction reduces the risk of unwanted friction that can lead to calluses. Nano bamboo charcoal fibers help keep your feet dry, which prevents infection. And they're non-binding. Dr. Comfort crew diabetic socks are available in white, and black. Features Non-Binding Top Nano Bamboo Charcoal Fiber Padding in Heel and Forefoot Y Toe Gore Eliminates Bunching Size Men Shoe Size Women Shoe Size Small 5 to 8 6 to 9 Medium 8.5 to 11.5 9.5 to 12.5 Large 12 to 15 13+