Patek Philippe 5205 G Annual Calendar, 5205G-001, 5205G 001, 18K white gold on a strap with an 18K white gold buckle, automatic movement, 48 hour power reserve, annual calendar, day, date, month, moonphase and 24 hour dial, centered sweep seconds hand, silver dial with applied stick markers, sapphire crystal, display back, water resistant to 30 Meters, diameter: 40mm, thickness: 13.55mm, Like New with Original Box and Papers dated 1 / 2012.

This is an 18K white gold Patek Philippe Annual Calendar, 5205G-001. The solid, two-body case, rounded bezel, and skeletonized lugs are all polished. There is a sapphire crystal snap-on case back, and the leather strap has an 18K white gold buckle. The two-tone dial is rhodium and ruthenium with applied oxidized gold faceted baton hour index markers, and matching dauphine hands. It has an outer track with engraved dot second/minute divisions, and a distinctive white sweep seconds hand. There is a subsidiary 24-hour dial ring at 6 o'clock, along with the moon phase aperture. The day of the week window is at 10 o'clock, the date is at 12 o'clock, and the month is at 2. It has a 45-hour power reserve at full wind, and it's water resistant to 30 meters.

The automatic Patek Philippe calibre 324 S QA LU 24H/206 movement is rhodium-plated with oeil-de-perdrix and fausses cotes embellishment, and the stamp of the Patek Philippe seal. It's constructed with 34 jewels, 356 components, 10 bridges, and a straight-line lever escapement. It has the patented Patek Gyromax balance that adjusts to cold, heat, isochronism, and 5 positions. There is a shock absorber mechanism and a self-compensating free-sprung flat balance spring. The mechanism oscillates at 28,800 vph (4 Hz), and the case, dial, and movement are all signed.

Patek Philippe received a patent for their Annual Calendar mechanism in 1996, while their annual calendar watch (only having to be manually adjusted once every 365 days) was selected watch of the year in the Basel show. This particular model is currently being produced.