Limited Edition Birkenstock SYDNEY. Straps are made from patent Birko Flor, Birkenstocks synthetic material with a soft felt backing, easy to clean. The photos may look like there are white spots on the straps but these are reflections because of the patent finish of the birko flor. COLOR: Green Glow. SIZE EU 40 US Women's 9 Men's 7. REGULAR width. I purchased online from an authorized Birkenstock retailer and have never worn. I am selling as I have a Gizeh that is a similar color that I have worn AND even though this is one of my favorite Birkenstock styles, I need to downsize my collection.