This 40mm annual calendar from Patek is a modern twist on a classic design. The triple date window layout for the calendar allows the dial to be as legible as possible and the detailing is as perfect as one would expect from Patek Philippe. The case being a good example a combination of delicately pierced lugs alongside a concave bezel is a rarely seen combination in the watchmaking world. The clear sapphire case back allows the owner to inspect the calibre 324 self-winding movement. The moon phase indicator sits at the 6 o'clock position surrounded by the 24-hour dial and the watch is water resistant down to 30 metres.