Birkenstock Unisex Arizona Sandals, Chrysanthemum Blue, Size 6.0 birko-flor Upper material: Leather  Thick yet supple leathers without additional dyes to keep the leather breathable durable and comfortable. Footbed: The original Birkenstock footbed - Featuring pronounced arch support deep heel cup and roomy toe box. Footbed molds and shapes to your foot. Sole material: EVA - Flexible lightweight durable and shock absorbing.