Birkenstock Boston Big Buckle Narrow Clog (Women) - Sandcastle NubuckMore buckle, more Boston. We're taking our beloved Big Buckle clog to the next level with the iconic Boston style. A large, shining buckle gives this laid back look a bold touch. Plus, with a molded footbed, these clogs will always feel like they were made just for you, no matter where you go. Contoured cork latex footbed creates custom support with wear Premium nubuck leather upper Suede footbed lining helps keep you comfortable EVA sole is flexible