Birkenstock Unisex Boston Oiled Leather ClogSize Chart The BIRKENSTOCK Boston is a veritable classic that can easily be worn all year round, which is why we added it to our Birkenstock Core Collection. The Boston has a legendary status thanks to its sophisticated, individual design. The upper is made from extra thick, oiled nubuck leather with an open selvage finish. Contoured cork latex footbed creates custom support with wear Oiled leather upper gives each pair a unique finish Suede footbed