Upper material: leather Inner material: leather Sole: thermoplastic rubber Closure: buckle Heel shape: flat Not waterproof. Available sizes: 3.5,5. Gioseppo Sandals NIOAQUE Available in women's sizes. by Gioseppo. There's nothing better for a hot summer day than a pair of sandals from Gioseppo. This design has a leather upper and synthetic sole. With their leather lining and leather insole, these shoes are very comfortable! The sun will shine again!