I received these last year, but they were too small from the start, so they're unused. I'm not sure of the size, so I tried them on myself. My foot size is 22.8cm, and they were tight, so I think they're children's socks, probably for 18-22cm feet. They were given to me as a gift for my fifth-grade son, so if they were for a girl, I'd guess they'd fit a 4th to 6th grader. The fabric is sturdy, and I think they can be worn year-round. I plan to ship via Yu-Packet Post Mini, but I may change it to Rakuraku Mercari Bin Nekopos.