BIRKENSTOCK. 1018 406. GIZEH BIG BUCKLE NUBUCK LEATHER. MUD GREEN. Meet the brand new Gizeh Big Buckle. This classic thong sandal gets a fresh update with an elegant amplified buckle. Feminine style that s comfortable and easy to wear. The footbed is lined with a coordinating soft tonal suede. The upper is made from high-quality nubuck leather.