I cannot vouch for the authenticity of these. I received them from a friend. These are in perfect condition. I wore twice once to the pool, and once on a brief dinner date. I have sensitive skin and these rubbed me the wrong way. Also fair warning these are extremely slippery at the pool! These are adorable and I really wish they could work out for me. Marked size 39/Size 9. These are pretty heavy, they are made out of a plastic style vinyl/rubber, which is very thick and durable. They look really cute with a pair of jeans, skirt, shorts. Casual with a flair.