Birkenstock Unisex Arizona Soft Footbed Leather Casual Sandals, Caribou Leather, 42 N nubuck Nubuck - Quality leather is buffed for a soft and velvety finish. The original Birkenstock footbed - Featuring pronounced arch support, deep heel cup, and roomy toe box. Footbed molds and shapes to your foot. EVA Sole - Flexible, lightweight, durable and shock absorbing.