These socks have a taping structure that supports the three arches of the foot. I used them a few times when I had plantar fasciitis, but I stopped using them now that it's healed because they feel too tight. L size (26-28cm) 《The following is the manufacturer's description》 These socks support the inner longitudinal arch, the outer longitudinal arch, and the transverse arch of the foot, reducing the collapse of the arches, which can easily cause foot-related problems. By supporting the arches, they not only absorb the impact on the legs when landing, but also allow the foot arches to act as springs, providing propulsion.