Pre owned Birkenstock Yao glossy black straps Size 40 Anyone who has a taste for unique fashion with a touch of extravagance will experience love at first sight with the Yao sandal from BIRKENSTOCK. The glossy patent leather surface makes the sandals an elegant favorite with a summer feel. The proven quality of the famous BIRKENSTOCK footbed, which supports the foot in its natural movement while simultaneously training your leg muscles with every step, remains unchanged.