Women's Birkenstock Slip on Sandal is made with Birko Flor upper cross-strap, toe loop with adjustable strap. Featuring cork latex footbed and shock absorbing EVA sole. Birko Flor is a material developed by Birkenstock as an alternative to leather. Birko Flor is made of soft acrylic and polyamide felt fibres with a durable smooth leather-like finish.