The Calatrava is the foundation of the Patek dress watch line and the 5227G-010 is a new model with an all-new Officer's style hinged case back which opens to reveal a sapphire case back displaying the self-winding movement. The watch is 39mm in diameter which is a welcome size for all those who have been calling for a larger self-winding Calatrava, by no means oversize but at the same time far from a dedicated dress watch. In this latest version, white gold with a black lacquered dial, Patek have produced an unusual watch that fills many peoples' requirements. For some a watch must have a black dial, less common for a number of reasons. Black is usually the colour of choice for formal dress dials.