18ct yellow gold Patek Philippe ref. 3440 Calatrava automatic wristwatch. Made 1966

The calibre 27-460M (“M” for Monodate) was an evolution of Patek Philippe’s first automatic calibre, the 12-600AT, which was fitted to the legendary reference 2526. The calibre 27-460M had received several upgrades, including a Gyromax balance wheel, a ball bearing, and some additional jewels. Over the ensuing years, three series were made with the first fitted with an acrylic crystal, similar to the present watch, the 2nd series made during the late 1970s featuring a higher bezel to accommodate a sapphire crystal, and the 3rd series featuring a sapphire display back. The model was also made with integrated bracelets, and offered with dials in silver, champagne, blue, and later with grey dial with white Roman numerals. Brand: Patek Philippe Made: 1966 Model: Calatrava Reference: 3440 Calibre: 27-460 Movement: Automatic Material: 18ct yellow gold Features/complications: Automatic movement Dial: Silvered dial with sunburst satin finish featuring outer minute track and baton hour indices with baton hands with subsidiary seconds at 6 o'clock Case dimensions: 34mm Bracelet/strap: Integrated 18ct yellow gold bracelet length approximately 182mm Accessories: - Additional information: N/A SKU: 3533