Patek Philippe 5004 Perpetual Calendar Split Second Chronograph, 5004J-012, 5004J, 18k yellow gold case is extremely thick and appears to be unpolished, all 4 hallmarks are deep and intact and clearly visible without magnification, the case is also starting to develop a charming patina, manual wind Patek Philippe 27-70Q movement with Geneva seal, 60-hour power reserve, gorgeous and perfectly balanced silver dial with applied yellow gold Arabic numerals, perpetual calendar function (English) with day, date, moon phase and leap year indicators, gold leaf hands, size 37mm, thickness 15mm. This example is in top collector condition with the original box, setting pin, additional solid caseback, archive certificate, and original certificate dated January of 2000.

This is an 18K yellow gold Patek Philippe Perpetual Calendar Split Second Chronograph, 5004J-012. It has an alligator leather st rap with an 18k yellow gold tang buckle. There is an exhibition screwed-down sapphire display case back, a case band with 4 correctors, Pump style chronograph pushers, and a co-axial pushbutton in the crown for the split-seconds function. The case is extremely thick and unpolished, and all 4 hallmarks are deep and intact and clearly legible. The 37mm diameter solid three-body case, fluted lugs, and angled bezel are polished/brushed. The dial is silver with applied yellow gold Arabic numeral hour markers and yellow gold feuille hands. There is a 1/5 second/minute outer track, and the perpetual calendar is in English. The day and month aperture windows are at the 12 oclock position, and there is a 30-minute chronograph totalizer with a leap-year cycle at 3 oclock. There is a moon phase sub dial at 6 oclock, and a small seconds stub dial with 24-hour time at 9 oclock. Its water resistant to 30 meters/100 feet, and it has a 60-hour power reserve at full wind. The 15mm thick case, dial, and movement are all signed. It is stamped with both the Geneva quality seal.

The mechanical manual winding Patek Philippe caliber 27-70Q movement is rhodium plated, with fausses cotes embellishment. Its constructed with 28 jewels, 10 bridges, and 407 components. It has a Glucydor Gyromax balance thats adjusted for temperature and 5 positions, a self-compensating Breguet balance spring, and a shock absorber mechanism. It oscillates at a frequency of 18,000 vph (3 Hz).

The Patek Philippe Perpetual Calendar Split Second Chronograph, 5004J-012, was introduced in 1996.