Birkenstock Siena Cross Strap Nubuck Leather Sandals Blue Size 40, Ladies 9-9.5 Narrow Siena boasts a refined appearance. Crossed straps give the sandal its unique and special look. The upper is made from high-quality nubuck leather that boasts a natural, rustic appearance. Upper: nubuck leather Footbed lining: suede Sole: EVA Details: two straps, one with an individually adjustable metal pin buckle Preowned condition with marks to straps, wear to footbeds and soles as pictured.