Amazing used condition Birkenstock Mayari sandals. Electric Metallic Blue. Size 39 8-8 1/2 The Mayari Birko-Flor is an effortless criss-cross design, with a single loop around the toe. Elegantly functional with two adjustable straps to ensure a perfect fit. Birko-Flor is a trade marked synthetic leather that is skin-friendly and easy to care for.