An expert in quality shoes, BIRKENSTOCK reveals its latest creation, the Boston Big Buckle. The brand has paid lots of attention to detail with its Nubuck leather upper and fashionable beige colour! From Nubuck leather on the upper level and a leather lining to which is added a leather insole.pour un rendu admirable. The brand has opted for a leather insole and a leather lining. All in all, the perfect pair to enhance your swagger and give you a deceptively casual look.