The Birkenstock Boston Exquisite. Featuring an exquisite footbed fully lined with soft piumato leather, paired with an upper made from high-quality aniline leather. The Birkenstock Boston Exquisite Is Final Sale. For most accurate sizing, refer to the Size Guide below. To keep your footwear fresh, spray the entire footbed with Birkenstock Cleaner & Refresher and wipe away excess moisture and dirt with a cloth. Brush suede and nubuck footbeds with a nubuck/suede brush to restore the nap. Apply Birkenstock Water & Stain Repellent regularly to protect upper Leather, Suede and nubuck from water and dirt. Brush uppers with a nubuck/suede brush to pull up dirt and dust and restore the nap.