Patek Philippe Ref. 3970 Platinum Patek Philippe, Genève, Ref. 3970EP. Made in 2003. Very fine and important, water-resistant, platinum wristwatch with black diamond-set dial, round button chronograph, register, perpetual calendar, moon phases, leap year, 24-hour indication and a platinum Patek Philippe deployant clasp. Accompanied by the original fitted mahogany box, Certificate of Origin, setting pin, booklet and a spare solid platinum case back. Three-body, solid, polished, concave bezel, fluted lugs, transparent screwed-down case back, sapphire crystals. Black with applied 10 round and 1 baguette diamond-set white gold indexes, subsidiary dials for the seconds, the 30-minute register, the days of the month, the 24 hours and the leap year, apertures for the days of the week, the months and the moon phases. White gold baton hands. Cal. CH 27-70/155, stamped with the Seal of Geneva quality mark, rhodium-plated, fausses cotes decoration, 24 jewels, straight-line lever escapement, Gyromax balance adjusted to heat, cold, isochronism and 8 positions, shock absorber, free-sprung self-compensating Breguet balance spring. Dial, case and movement signed. Diam. 36 mm. Thickness 13 mm. Notes Ref. 3970 (1986-2005) This Reference was introduced, for Patek Philippe's 150th anniversary, to replace Ref. 2499, which was produced from 1951 to 1985. The Series: As a general rule, the Ref. 3970 was produced in 18K white, rose, yellow gold, and platinum, with the latter being the rarest.