Size 40 - never worn. From post-workout to pool days—the BIRKENSTOCK Honolulu is the perfect on-the-go thong sandal. Made completely from ultra-lightweight EVA, this style is waterproof and flexible to keep up with your everyday. Anatomically shaped BIRKENSTOCK footbed made from EVA Made from a single piece of molded EVA Waterproof and ultra-lightweight “Made in Germany” stamp on footbed