Outer: Organic leather. Inner: Organic leather. Inner sole: Organic leather. Outer sole: Rubber. Closing: Velcro strap. Interior dimensions: EU24 (ca 152mm) EU25 (ca 159mm) EU26 (ca 166mm) EU27 (ca 173mm) EU28 (ca 181mm) & Euml;U29 (ca 188mm) EU30 (ca 194mm)