A FINE AND RARE PINK GOLD AUTOMATIC CENTER SECONDS PERPETUAL CALENDAR WRISTWATCH WITH RETROGRADE DATE AND MOON PHASES, Patek Philippe & Co., Genève, NO. 1957701, REF. 5050, CIRCA 1998

18k, rhodium plated lever movement (Calibre 315S QR) stamped with the seal of Geneva, 31 jewels, free-sprung gyromax balance, adjusted to heat, cold, isochronism and 5 positions, silvered matte dial with applied Roman numerals, apertures for day, month and leap year indicator, retrograde date, sector with moon phases, white gold leaf hands, water-resistant type circular case with screw-down back, sapphire crystal display back, case, dial and movement signed, with an 18k pink gold Patek Philippe deployant clasp.

Ref 5050

Ref. 5050 is another example of a magnificent automatic perpetual calendar, with around 1000 pieces made.  Less than one fifth of those produced come with Roman numerals on the dial. Ref. 5050 bears the calibre 315 136 (SQR), which is the descendant of the caliber 27'460 of Ref. 3448. It appears that the platinum-made version is the rarest example.