Birkenstock Two-Strap Slingback Sandal (black) Milano Oiled Leather Sandal Women Size 40 (9) Men Size (7) ▶️ Used Condition- lots of life left The oiled leather uppers consist of two straps across the top of your foot and a heel strap, all of which are adjustable to deliver an ultra customized fit. The classic Birkenstock footbed is anatomically correct, made of latex and 100% renewable and sustainable cork. The Birkenstock footbed is suede lined and will mold to the shape of your foot, creating a shoe that is made just for you.