These are compression socks from Okamot's. They use patented spiral compression to push the blood accumulated in the calves back to the heart. Recommended for those who stand for work, sit for work, or those whose legs tend to swell. These socks have a right and left, so please wear them according to the R (right) and L (left) markings on the inside of the cuff. To ensure proper compression, align the heel position and adjust the LR mark to the center of the neck. Size: 23-25cm Color: Black *The outer packaging bag is not included to make the packaging more compact. Please understand this before purchasing. Only the socks themselves are included, but they are definitely new and unused products. We will ship via Yu-Packet Post Mini on the same day or the next day.