Baume et Mercier Watch Riviera Automatic Skeleton 10721. The Riviera 10721 reveals an openworked mechanism in a satin-polished stainless steel dodecagonal 42mm case and a scratch-resistant sapphire crystal on both sides. Fastened by four screws in sandblasted ADLC-coated steel, the bezel glows in polished and sun-satin stainless steel. The built-in black rubber strap features a canvas pattern and is interchangeable without the need for tools.