- colour: nude natural 100% natural cow leather, goat skin lining, foamed rubber sole AVIR means air. They are soft leather shoes on a lightweight and comfortable sole. AVIR is suitable for every day’s fast pace. *When choosing the size keep in mind that the leather we use for making our shoes is very soft, with time it stretches and adjusts to the foot shape. Opera and Avir models should hold the foot tightly “like a sock” at first. Due to this we recommend choosing smaller size.