NWT Sorel Ella Slingback Mule Sandals Black Size 8.5. A slingback sandal with a molded footbed designed for comfort, this black metallic suede pair is waterproof and perfect for exploring new cities or running errands in Features an EVA footbed with soft lining for a pack light and travel far design. They can be dressed up or down and they look good with almost any outfit. New in the box.