百達翡麗，精細及非常罕有，18k紅金自動上弦腕錶，配世界時間及掐絲琺瑯錶盤，型號5131，約2016年製

The yellow gold version of reference 5131 was launched in 2008, followed by white gold in 2009 and later pink gold such as the present example in 2014. The dial of the present yellow gold example represents the Americas, Europe and Africa, the white gold version shows Europe, Africa, Asia, and Oceania, and finally the dial of the pink gold version shows Asia, Oceania and the Americas.

Reference 5131 is the successor of reference 5130 and shows three notable differences: use of a distinguishable closionné enamel dial, the names of the 24 cities are displayed in Italic type and the signature Patek Philippe and company location Genève are engraved on the bezel. Only two or three enameller artists are able to produce these rare dials and together they can only deliver 30-40 dials of each color every year. In 2012 a special and unique reference 5131 was produced with a view of Lake Geneva, to celebrate the firm's 175th Anniversary. In 2014, limited editions with different dial motifs were launched.

Reference 5131 is equipped with the ultra-thin automatic calibre 240 HU (HU for Heure Universelle, French for World Time). It features an eccentric 22K gold micro-rotor recessed in the back plate.

A modern world time wristwatch, the mechanism dates back to the 1930s when talented Geneva watchmaker Louis Cottier devised it and offered his invention to Patek Philippe. Cottier's ingenuity resulted in the company's now classic references 1415 HU and 2523. In 1959, Patek Philippe obtained a patent for Cottier's device (Swiss Patent No. 340 191). The company further developed the movement, introducing calibre 240 HU in 1999.