The Patek Philippe 5004J is one of the most iconic and sought-after perpetual calendar split seconds chronographs ever produced, encapsulating the end of an era defined by exquisite hand-finishing and technical mastery. Issued in 18K yellow gold, the 5004J boasts the legendary hand-wound calibre CHR 27-70 Q, which includes a rattrapante chronograph and perpetual calendar (Spanish) complication—features seldom united with such poise. This example was born on a silver dial, and the owner commissioned an additional black dial, a common practice with Patek Philippe in the 1990s and 2000s. The yellow gold case is in excellent original condition, showcasing its original lines and details, and only light signs of restoration. A yellow gold black dial 5004 is one of the most desirable combinations for elite Patek Philippe collectors. Born from the revered Lemania base, the movement is artfully finished by Patek Philippe's artisans and hous ed in an elegant, perfectly proportioned 37mm case. Produced from the mid-1990s through 2012 in very limited numbers—estimated at just a few hundred in yellow gold—special dial variants rank among the rarest. The 5004 marked Patek's last perpetual calendar split seconds chronograph using a classical approach, succeeded by the fully in-house 5204. Its investment-level rarity, mechanical pedigree, and special-order provenance render it a prize centerpiece, especially in this rare black dial configuration. Discerning collectors recognize the 5004J for its nuanced technical complexity and historical significance at the apex of modern haute horlogerie. This particular example is accompanied by a Patek Philippe box, original solid caseback, original silver 5004 dial, and original certificate dated May / 2000.