This formal shoe has an insole that is 6 mm thick, making it even more comfortable. It fits the foot perfectly. The sole is made of TPU (a very durable and flexible material) and all these features make the design Empire a great success. Upper: 100% calf leather Inner lining: 75% pig leather and 25% textile Sole: 100% synthetic Removable insole Type of closure: Sole thickness 3.7 cm (1.46'') Additional comfort