The Rotonde de Cartier is a classic beauty, with a round case and simple lugs that stay true to the brand's signature style. This collection is all about adding extra special features to their timepieces. Take the Rotonde Calendar Aperture and Power Reserve, for example. As the name suggests, it has a handy date aperture and a power reserve indicator. The W1556369 model boasts a stainless steel case and a sleek silver dial. It's a perfect blend of traditional and modern elements.