Castelli Free X9 Sock
Let's face it: there's always a good time to upgrade your sock drawer and experience revolutionary comfort. The top of the foot is ultra-thin and extremely breathable. In the middle of the foot, the arch area, there is a high-density band woven in. You won't notice any difference in thickness, but you will feel like the sock is becoming one with your foot rather than sliding around between your foot and your shoe. The sock has a flat seam on the toe for comfort and a compression cuff.