100% natural, breathable leather upper and lining + premium comfort soft leather insole with durable and flexible synthetic sole. Like all natural, breathable leathers, this will adapt to your foot over time, even changing with you from morning until night as your feet swell slightly the longer you are on them. These are medium-width shoes, but will stretch slightly to accommodate a wider footbed as well. If you need a half-size, consider buying the next size down since the leather will stretch slightly to accommodate you.