The Birkenstock Sienna Big Buckle sandals in women's size 39 (US 8-8.5) feature a metallic gold buckle, making them perfect for travel, activewear, or casual occasions. These sandals have a flat heel style and are made with leather upper and insole material, with a rubber outsole for durability. Designed by Birkenstock in Germany, the Sienna Big Buckle sandals offer both style and comfort for women looking for a unique and versatile footwear option.