A size 40 Birkenstock Arizona Soft Footbed is a unisex sandal with a classic, two-strap design, featuring a cork footbed with an integrated latex foam layer for added cushioning and instant comfort. It typically has an upper of suede, leather, or Birko-Flor™, an EVA sole, two adjustable metal pin buckles, and a deep heel cup for stability. Size 40 is equivalent to a US Women's 9-9.5 or a US Men's 7-7.5.