Birkenstock ankle strap. The sandal comes with two inner changeable leather designs that snap on to the sandal itself. The first is fringe and the second is a floral pattern. Or wear no topper. All leather and cork. i tried these on i wear a 36 / 6 yet this 35 fits like a glove on me. Maybe they run a little large. They are unique and rare. Very cute, natural and comfortable. If your a 6 you might get lucky to have theses cuties in your closet.