The Madrid Big Buckle Nubuck Leather Narrow from Birkenstock is a stylish model with one strap and large decorative buckles, in an elegant off-white color. True to size. Model: Madrid Big Buckle Narrow with a firm footbed. Material: - Anatomically shaped cork/latex footbed - Lining: suede leather - Sole: EVA - Details: strap with adjustable oversized metal buckle.