Yume Yume Ballerina Flats in Grey - BA0004. Inspired by the elegant design of the classic ballet shoe, our Ballerina Flats feature signature puffiness and wrinkles from our Camp shoes. These flats come with removable straps made of vegan leather and silk material. Upper: Vegan leather (60% PU, 40% PU), Straps: Silk (72% VI, 28% SE), Lining: 100% Microfiber, Outsole: 100% Leather.