The Birkenstock Boston clog is a veritable classic that can easily be worn all year round. The color-coordinated outsole rounds off the look of sophistication. This popular sandal has been given an update in a new material, with a vegan version now available. It is entirely free of animal products, as verified by independent testing laboratories. The upper is made from the skin-friendly, hard-wearing synthetic material Birko-Flor in a sophisticated nubuck look.