Basel 2008: Patek Philippe Ref. 5139G Perpetual Calendar Watch

The Patek Philippe Ref. 5139G watch presents the brand's classical hobnail-patterned perpetual calendar in a new, slightly enlarged format.  The 18K white gold case of this impeccably elegant timepiece measures 38mm in diameter, an increase of almost 3mm over the previous model--the Ref. 5039G.  The size emphasizes the sleek elegance of the rhodiumed opaline dial, with its impeccably organized calendar indications, and slender baton hour markers and leaf shaped hands in polished white gold.  The gently curved sapphire crystal is surrounded by the distinctive bezel, which is adorned with the classical "Clous de Paris" guilloche pattern.

Patek Philippe is well known for its mastery of classical complications, and the perpetual calendar is one of their best known.  The Ref. 5139G watch keeps track of the day, date, month, leap year, and moon phases; the complex mechanism self-corrects for the various lengths of months, as well as the various changes that occur through the leap year cycle.  These functions are governed by the manufacture 240 Q caliber.  Despite its 275 individual components, the 240 Q is only 3.88mm in height, a factor which is partially attributable to the 22K gold microrotor.  The caliber features a Gyromax balance wheel that beats at a pace of 21,600 alternations per hour, and power reserve of the movement is approximately 48 hours.  A sapphire crystal window in the caseback allows a glimpse into the richly decorated mechanism, which has earned the Geneva Seal for its conformation to the traditional standards of high watchmaking dictated by Canton of Geneva since 1886.

The Patek Philippe Ref. 5139G Perpetual Calendar watch is fitted with a crocodile strap and a white gold folding clasp, and each is supplied with a second, interchangeable solid caseback.  Water resistance of this model is rated at 30 meters.