Omega Constellation Megasonic 720 Hz.
Chronometer! in N.O.S. condition.
A new battery is fitted and running perfectly!
Not humming but whistling because it is 720 Hz.
Scratch free glass, full-length strap, correct date change a beauty!
I can tell a lot of these watches but this site will give you the best and the most info,
A great site!
Size excl. the signed crown 36,5 mm.
Great silvered dial with a coin edge bezel