Betula b Birkenstock Mia stylish, ergonomically designed slide sandal featuring an asymmetrical toe-loop and adjustable strap. As a licensed diffusion line of Birkenstock, Betula features the same contoured cork footbed for excellent arch support, making it a popular choice for all-day comfort at a more affordable price point. Footbed: Anatomically shaped cork and latex designed to mold to your stride. Upper: Crafted from synthetic Birko-Flor, which is durable, wipeable, and mimics the look of leather. Brand New with Tags. Size 37/6.5