Birkenstock Classic Series Dark Brown Vintage Casual Buckle Sandals. The upper is crafted from high-quality full-grain cowhide. The footbed adopts the brand’s iconic ergonomic natural cork technology, which fits the arch of the foot well and keeps you comfortable even after long hours of wear. The vintage brown tone is highly versatile and matches all kinds of summer outfits. It is a hugely popular street-style item in the fashion circle, strikes a great balance between comfort and trendiness, is loved by fashionistas around the world, and is the iconic classic that earned Birkenstock its widespread reputation.