This item was given to me by an acquaintance, so the size is unknown, but I think it's probably around M. I wore it once in the spring, but it was too tight for me, who wears L size, and I couldn't move. The neck was tight, so I made a cut in it, so please understand this before purchasing. (See photo 3) Water did not seep in. The rubber is a little stiff, but there are no other tears or holes, and it seems like the previous owner didn't use it much. I apologize for the lack of information, but I will sell it at a low price, so please understand.