The stylish Castelli Endurance 15 socks are built to last, with a double needle construction that makes them more dense, finer, and more luxurious against the skin. They are also highly resistant to wear and tear, thanks to the reinforced heel and toe. Despite their durable design, these socks are incredibly comfortable. They are smooth and cozy, with cushioning under the foot and a supportive band to keep your feet supple. Made from bioceramic yarns, they not only provide all-day comfort, but also help you cycle faster and longer.Key features include a 15cm leg length, fine and strong construction using 200 needles, bioceramic yarns for added comfort, under-foot cushioning, a reinforced heel and toe, and a midfoot support band.