These are Aquamarine socks from biarms. The size is M. My shoe size is 23.5-24cm, so please use that as a reference. I purchased these 15-20 years ago and used them a few times, but they have been stored at home ever since. They are perfect for river play, swimming in the sea, bodyboarding, diving, snorkeling, etc. Please understand that these are used items from quite a while ago before purchasing. Instant purchase OK.