Uses a plastic buckle for fastening. The problem is that the buckle is on the outside of the sandal. You cannot reach and clasp your right sandal with your left hand, so you must crouch or sit down to clasp the sandal with your hand on the same side as the sandal. (right sandal - right hand) If you wear them, they are beautiful. The problem is turning them on and off. So if you like tying yourself in a knot to close your sandals, this could be for you? Otherwise I would have gone further.