their running shoes. I normally wear an 11 in their women's running shoes & have even had to buy a men's shoe because sometimes even that feels too tight. With the Nike Straprunners that I have, I very comfortably fit into a 10 which is my normal size for shoes. They are great!!! Most comfortable sandles that I have ever owned!!! I wore them in & out of water last yr & they still look like new.
Good luck.
ps, I got mine at a Nike outlet last summer so if you have one in your area or could call & order by phone, I found them to be pretty cheap.