GAIA PE This women's BIO sandal is made of leather. The sole is made of cork and 3 cm EVA rubber. The inner sole is lined with breathable fabric for greater comfort. It features a toe strap and a top strap with an adjustable buckle for a perfect fit. This model fits true to size; if you are between two, we recommend choosing the smaller size. GAIA PE This women's BIO sandal with buckle is made of leather. It features a toe strap and a top strap with an adjustable buckle for a perfect fit. A timeless and comfortable model for the most simple plans. This model fits true to size; if you are between two, we recommend choosing the smaller size.