Upper material: Birko-Flor - Made of acrylic and polyamide felt fibers, this material is a soft fabric with a smooth leather-like finish. Footbed: The original Birkenstock footbed - Featuring pronounced arch support, a deep heel cup and a roomy toe box. Covered with a suede liner. The footbed molds and shapes to your foot. Sole material: EVA - Flexible, durable, lightweight, shock resisting soling material.