A640 Steel Toe Polyurethane in Color Black | BIRKENSTOCK US。Birkenstock A 640 professional clogs offer maximum safety and comfort for demanding work environments. These work shoes feature a durable polyurethane upper that is resistant to oil and grease, paired with a non-slip PU outsole for stable footing. The anatomically shaped cork-latex footbed is lined with moisture-wicking leather, while the integrated steel toe cap provides essential protection. Designed with a medium fit, these clogs are water-resistant and easy to clean, making them ideal for kitchens and medical settings.