This Birkenstock Women’s Gizeh Black Thong Sandal is an adult flip-flop in a US women’s size 6.5. It is made from black leather and features a buckle that is adjustable to properly secure the sandal to your foot. The width of the sandal is medium. This is a flat sandal designed to be worn on casual occasions or as everyday footwear. It features Birkenstock’s comfortable footbed, which is designed to provide support and conform to your foot.