The Birkenstock Women's Gizeh Birko-flor Casual Sandals are Birkenstock's traditional thong flip-flops where the toes have more freedom. The upper is made of Birko-Flor which is soft fabric that has a smooth like finish. The fully adjustable strap allows for a great fit and maximum comfort. The signature Birkenstock footbed features a toe bar that allows the toes to grip and flex to maintain circulation and balance.