1966 Omega Constellation Date Automatic Chronometer Model 1685416 in 18ct Gold Case with Box and PapersThis Watch This Omega Constellation is one of the most stunning Constellation sets we've seen! It features a rare and beautiful, solid 18ct yellow gold, screw back case which houses the ever reliable, automatic Omega caliber 561 chronometer rated movement, fully serviced by us and running strongly. The original dial has the date function at 3 o'clock and is signed 'Omega, Automatic, Chronometer, Officially Certified' at 12 o'clock and 'Constellation'