Cal. 315 S IRM QA LU (SI) automatic movement, stamped with the seal of Geneva, 36 jewels, silicon escape wheel, silvered dial, applied black Arabic numerals and baton indexes with luminescent dots, luminescent Feuille hands, center seconds, subsidiary dials for day and month, fan form aperture for moon phases, aperture for date at 6, power reserve indicator at 12, outer minute track, 18k white gold case, sapphire crystal display back with integrated magnifying lens inscribed Patek Philippe Advanced Research, case, dial, and movement signed, with an 18k white gold Patek Philippe folding clasp.

Accompanied by an Extract from the Archives confirming the date of sale on 20 December 2005.

Patek Philippe’s Advanced Research division is devoted to technical innovations for the future of horology. The development of Silinvar, an ultra-modern silicon technology, improves upon Patek Philippe’s mastery in precision and efficiency. Previously, hairsprings and other vital parts made from carbon steel were susceptible to oxidation, rust, magnetism, and temperature variations. The development of Silinvar eliminates these variables with the added benefit of reduced mass. Silinvar is in fact three times lighter than conventional carbon steel springs, transmits energy more efficiently, and can be shaped more accurately, making it an ideal material for watchmaking

The Ref. 5250 was launched in 2005 in a limited series of only 100 examples in white gold.

The present lot is factory sealed and has not been tested for accuracy or duration of the power reserve. The movement runs. In like-new condition, single sealed in factory plastic wrap. Factory two part box is present.

Please be advised that bands made of materials derived from endangered or otherwise protected species (i.e., alligator and crocodile) are not sold with the watches and are for display purposes only. We reserve the right to remove these bands prior to shipping. Please note that the watch is in white gold.

Please note that the present lot is being offered in its original factory seal. Because the strap must be removed in order for the watch to be shipped out of the United States, the factory seal will need to be broken. Buyers should be aware that breaking the seal may cause the lot to decrease in value.