A jewellery version of a Patek Philippe classic, Reference 5271/12P-010 is lit up by 80 baguette-cut rubies (5.25 cts) set on the bezel, the lugs and the fold-over clasp. The intense colour of the gems is echoed by the lacquered red dial with black-gradient rim and the shiny black alligator strap with contrasting stitching. The CH 29-535 PS Q caliber is distinguished by its traditional architecture (manually wound, column wheel, toothed-wheel horizontal clutch), combined with six patented innovations in the chronograph, as well as its exceptionally slim calendar mechanism.