- colour: black 100% natural cow leather, goat skin lining, rubber sole OPERA shoes are elegant and classic. Stylish sole on a small heel is lightweight and flexible. *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.