Upper material: Birko-Flor - a synthetic material made of acrylic and polyamide felt fibers that is comfortable and tear resistant. This material has a synthetic leather-like finish with felt lined backing. Wipes clean with mild soap and water. Footbed: The classic Birkenstock footbed - features pronounced arch support, a deep heel cup, and a roomy toe box. The footbed conforms to the shape of your foot. Sole material: EVA - flexible, lightweight, durable and shock absorbing.