Birkenstock Gizeh Sandal – Birko-Flor Graceful Pearl White Size 40 9 Women's Gizeh Adjustable Strap Thong Sandals Birko-Flor® upper: Made of easy-to-care-for and hygienic PVC, which has been lined on the inside with a soft, breathable layer of fleece. This high-quality material is very gentle on the skin, comfortable, and very durable. adjustable strap with buckle slip on styling soft lining suede-lined foot-conforming footbed with pronounced arch support, a deep heel cup, and a roomy box toe flexible, lightweight EVA outsole for shock resistance and durability