Birkenstock Unisex Arizona Soft Footbed Sandal Synthetic Birko-Flor Upper. Birkenstock Arizona Birko-Flor Soft Footbed Sandals, Basalt (a Dark Greyish/Blueberry Blue like color), Unisex, 40 M EU (US Women Size 9-9.5 or US Men Size 7-7.5) Soft Footbed features an extra layer of cushioning foam built into legendary Birkenstock footbed. Birkenstock Arizona Black Birko-Flor Upper; Unisex Sandal. Arizona from Birkenstock is a classic two-strap style with fully adjustable straps and shock-absorbing EVA sole. Anatomically correct cork footbed that is both renewable and sustainable. Made in Germany by Birkenstock.