Birkenstock Birki Flow EVA Clogs. Introducing Birkenstock's first post-sport recovery clog, the all-new Birki Flow. Designed around the contours of our iconic footbed, the Birki Flow builds off our best-selling EVA clogs with an ultra-breathable, water-friendly style. Complete with classic BIRKENSTOCK® design cues, from the adjustable backstrap to molded buckle. Contoured footbed made from EVA. Water-friendly design with breathable vents. washable, flexible & ultra-lightweight. Imported.